<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2024 Workiva-->
<!--r:35bc2e6d-66e0-4d25-aea0-0a5a8df7dc3a,g:ec401b8d-9f80-4bea-9fd8-42d69a77b5cc-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="simple" xlink:href="moh-20240331.xsd#CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/CONSOLIDATEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_862549a2-7214-459b-abc6-6f03bb47761f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_d706a86c-3a53-4e70-bae6-d6893a802840" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_862549a2-7214-459b-abc6-6f03bb47761f" xlink:to="loc_us-gaap_StatementTable_d706a86c-3a53-4e70-bae6-d6893a802840" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_9b216bec-b089-4d16-9bb5-392da9feae4e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_d706a86c-3a53-4e70-bae6-d6893a802840" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_9b216bec-b089-4d16-9bb5-392da9feae4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_9b216bec-b089-4d16-9bb5-392da9feae4e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_9b216bec-b089-4d16-9bb5-392da9feae4e" xlink:to="loc_us-gaap_EquityComponentDomain_9b216bec-b089-4d16-9bb5-392da9feae4e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_a75529ff-9354-4ee1-8af4-ecf9e86402e4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_9b216bec-b089-4d16-9bb5-392da9feae4e" xlink:to="loc_us-gaap_EquityComponentDomain_a75529ff-9354-4ee1-8af4-ecf9e86402e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_a3028d26-c0a4-48ed-a80b-a95b05e67bdc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a75529ff-9354-4ee1-8af4-ecf9e86402e4" xlink:to="loc_us-gaap_CommonStockMember_a3028d26-c0a4-48ed-a80b-a95b05e67bdc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_7568158d-9b2b-49b4-913e-7f02833bdda5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a75529ff-9354-4ee1-8af4-ecf9e86402e4" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_7568158d-9b2b-49b4-913e-7f02833bdda5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_b5523ee0-7686-452b-80ef-3b3f97538a81" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a75529ff-9354-4ee1-8af4-ecf9e86402e4" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_b5523ee0-7686-452b-80ef-3b3f97538a81" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_b834e36d-3da1-44d9-bc29-d0279158d989" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a75529ff-9354-4ee1-8af4-ecf9e86402e4" xlink:to="loc_us-gaap_RetainedEarningsMember_b834e36d-3da1-44d9-bc29-d0279158d989" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6e4a5db6-37c0-48fd-bef1-464cd7533e47" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_862549a2-7214-459b-abc6-6f03bb47761f" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6e4a5db6-37c0-48fd-bef1-464cd7533e47" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_9d688cba-ef96-4c7a-af34-104fc6009dc6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6e4a5db6-37c0-48fd-bef1-464cd7533e47" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_9d688cba-ef96-4c7a-af34-104fc6009dc6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_e1471e2b-4e9f-4a3e-aad6-40cc18e51dbb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6e4a5db6-37c0-48fd-bef1-464cd7533e47" xlink:to="loc_us-gaap_StockholdersEquity_e1471e2b-4e9f-4a3e-aad6-40cc18e51dbb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_34a12a5b-25d8-4ac8-890b-4e0eaf7e2571" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6e4a5db6-37c0-48fd-bef1-464cd7533e47" xlink:to="loc_us-gaap_NetIncomeLoss_34a12a5b-25d8-4ac8-890b-4e0eaf7e2571" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_b8b0ffd1-b760-4902-85a0-b8c7c5bbda8e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6e4a5db6-37c0-48fd-bef1-464cd7533e47" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_b8b0ffd1-b760-4902-85a0-b8c7c5bbda8e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_dbe57632-ea9e-44a3-b224-4e71af5624ca" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6e4a5db6-37c0-48fd-bef1-464cd7533e47" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_dbe57632-ea9e-44a3-b224-4e71af5624ca" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_fb1f653e-9d87-4c86-b2c6-7a0b9c1b1e02" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_6e4a5db6-37c0-48fd-bef1-464cd7533e47" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_fb1f653e-9d87-4c86-b2c6-7a0b9c1b1e02" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_6bd9fa18-8b18-4102-aba3-d172f283e868" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_eb4f210e-e9f0-4c84-8817-e994cbd513f1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/OrganizationandBasisofPresentationDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#OrganizationandBasisofPresentationDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/OrganizationandBasisofPresentationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_37448f13-ae2c-4b74-9783-b94fd4d0e28f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_dda15bf2-6f50-447e-8cb2-349b713ac633" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_37448f13-ae2c-4b74-9783-b94fd4d0e28f" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_dda15bf2-6f50-447e-8cb2-349b713ac633" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_ea972364-ec27-49fb-b362-84090e65c617" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_dda15bf2-6f50-447e-8cb2-349b713ac633" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_ea972364-ec27-49fb-b362-84090e65c617" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_ea972364-ec27-49fb-b362-84090e65c617_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_ea972364-ec27-49fb-b362-84090e65c617" xlink:to="loc_us-gaap_SegmentDomain_ea972364-ec27-49fb-b362-84090e65c617_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_04026eb5-f6b1-42f3-882b-9fb45ef8a3da" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_ea972364-ec27-49fb-b362-84090e65c617" xlink:to="loc_us-gaap_SegmentDomain_04026eb5-f6b1-42f3-882b-9fb45ef8a3da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_HealthPlansMember_455f9dab-5298-4331-bd3b-82fa1488ad7d" xlink:href="moh-20240331.xsd#moh_HealthPlansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_04026eb5-f6b1-42f3-882b-9fb45ef8a3da" xlink:to="loc_moh_HealthPlansMember_455f9dab-5298-4331-bd3b-82fa1488ad7d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MedicaidMember_ade10415-c823-4e34-be81-2c080767471c" xlink:href="moh-20240331.xsd#moh_MedicaidMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_04026eb5-f6b1-42f3-882b-9fb45ef8a3da" xlink:to="loc_moh_MedicaidMember_ade10415-c823-4e34-be81-2c080767471c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MedicareMember_2c209d8c-30ce-4634-9395-0671bf4cb5c0" xlink:href="moh-20240331.xsd#moh_MedicareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_04026eb5-f6b1-42f3-882b-9fb45ef8a3da" xlink:to="loc_moh_MedicareMember_2c209d8c-30ce-4634-9395-0671bf4cb5c0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_79c84478-a4af-4463-a0aa-db1b26ad2ac8" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_dda15bf2-6f50-447e-8cb2-349b713ac633" xlink:to="loc_srt_RangeAxis_79c84478-a4af-4463-a0aa-db1b26ad2ac8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_79c84478-a4af-4463-a0aa-db1b26ad2ac8_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_79c84478-a4af-4463-a0aa-db1b26ad2ac8" xlink:to="loc_srt_RangeMember_79c84478-a4af-4463-a0aa-db1b26ad2ac8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_77147ede-cc56-4a46-9b10-b4937788b98f" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_79c84478-a4af-4463-a0aa-db1b26ad2ac8" xlink:to="loc_srt_RangeMember_77147ede-cc56-4a46-9b10-b4937788b98f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_f8ded058-7f6a-4d04-b24a-71db115a43a3" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_77147ede-cc56-4a46-9b10-b4937788b98f" xlink:to="loc_srt_MinimumMember_f8ded058-7f6a-4d04-b24a-71db115a43a3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_940d2ee9-5373-4737-84a3-c7dac323fdfd" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_77147ede-cc56-4a46-9b10-b4937788b98f" xlink:to="loc_srt_MaximumMember_940d2ee9-5373-4737-84a3-c7dac323fdfd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_c6afcb11-c419-4ea6-bd57-3c5a5d4c3de3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_dda15bf2-6f50-447e-8cb2-349b713ac633" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_c6afcb11-c419-4ea6-bd57-3c5a5d4c3de3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c6afcb11-c419-4ea6-bd57-3c5a5d4c3de3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_c6afcb11-c419-4ea6-bd57-3c5a5d4c3de3" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c6afcb11-c419-4ea6-bd57-3c5a5d4c3de3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5029f6ce-00d8-4cdc-98b6-7bcc9adedf62" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_c6afcb11-c419-4ea6-bd57-3c5a5d4c3de3" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5029f6ce-00d8-4cdc-98b6-7bcc9adedf62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_BrandNewDayAndCentralHealthPlanOfCaliforniaMember_de030d66-b70e-4bc8-b288-5dde43284db3" xlink:href="moh-20240331.xsd#moh_BrandNewDayAndCentralHealthPlanOfCaliforniaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5029f6ce-00d8-4cdc-98b6-7bcc9adedf62" xlink:to="loc_moh_BrandNewDayAndCentralHealthPlanOfCaliforniaMember_de030d66-b70e-4bc8-b288-5dde43284db3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_69f2d3ba-ec58-46cb-a1c3-f09ba74a6e87" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_dda15bf2-6f50-447e-8cb2-349b713ac633" xlink:to="loc_srt_StatementGeographicalAxis_69f2d3ba-ec58-46cb-a1c3-f09ba74a6e87" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_69f2d3ba-ec58-46cb-a1c3-f09ba74a6e87_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_69f2d3ba-ec58-46cb-a1c3-f09ba74a6e87" xlink:to="loc_srt_SegmentGeographicalDomain_69f2d3ba-ec58-46cb-a1c3-f09ba74a6e87_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_1983f82e-2754-4106-b3ba-2e488ad4835e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_69f2d3ba-ec58-46cb-a1c3-f09ba74a6e87" xlink:to="loc_srt_SegmentGeographicalDomain_1983f82e-2754-4106-b3ba-2e488ad4835e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_stpr_MI_69d0940a-7480-4976-a7a1-1432780f9d7d" xlink:href="https://xbrl.sec.gov/stpr/2023/stpr-2023.xsd#stpr_MI"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1983f82e-2754-4106-b3ba-2e488ad4835e" xlink:to="loc_stpr_MI_69d0940a-7480-4976-a7a1-1432780f9d7d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_stpr_MS_47b41051-eb6a-4b7d-84f0-d845cf01ea19" xlink:href="https://xbrl.sec.gov/stpr/2023/stpr-2023.xsd#stpr_MS"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1983f82e-2754-4106-b3ba-2e488ad4835e" xlink:to="loc_stpr_MS_47b41051-eb6a-4b7d-84f0-d845cf01ea19" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_stpr_VA_92038b24-3e33-4128-8e5b-7be1aadfb0cb" xlink:href="https://xbrl.sec.gov/stpr/2023/stpr-2023.xsd#stpr_VA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_1983f82e-2754-4106-b3ba-2e488ad4835e" xlink:to="loc_stpr_VA_92038b24-3e33-4128-8e5b-7be1aadfb0cb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_457c2157-0fb2-4421-a6db-bee27f84038e" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_dda15bf2-6f50-447e-8cb2-349b713ac633" xlink:to="loc_srt_CounterpartyNameAxis_457c2157-0fb2-4421-a6db-bee27f84038e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_457c2157-0fb2-4421-a6db-bee27f84038e_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_457c2157-0fb2-4421-a6db-bee27f84038e" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_457c2157-0fb2-4421-a6db-bee27f84038e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_59bacb19-8e87-4dfa-9a6d-73a6f8605c35" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_457c2157-0fb2-4421-a6db-bee27f84038e" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_59bacb19-8e87-4dfa-9a6d-73a6f8605c35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MichiganDepartmentOfHealthAndHumanServicesMember_3a8f6835-3dc9-41a5-a628-a62451b2088a" xlink:href="moh-20240331.xsd#moh_MichiganDepartmentOfHealthAndHumanServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_59bacb19-8e87-4dfa-9a6d-73a6f8605c35" xlink:to="loc_moh_MichiganDepartmentOfHealthAndHumanServicesMember_3a8f6835-3dc9-41a5-a628-a62451b2088a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MississippiDivisionOfMedicaidMember_34618794-fdb2-4231-8b66-1fe5314c8684" xlink:href="moh-20240331.xsd#moh_MississippiDivisionOfMedicaidMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_59bacb19-8e87-4dfa-9a6d-73a6f8605c35" xlink:to="loc_moh_MississippiDivisionOfMedicaidMember_34618794-fdb2-4231-8b66-1fe5314c8684" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_VirginiaDepartmentOfMedicalAssistanceServiceMember_461cd3e9-acb2-4696-a545-9f023399beec" xlink:href="moh-20240331.xsd#moh_VirginiaDepartmentOfMedicalAssistanceServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_59bacb19-8e87-4dfa-9a6d-73a6f8605c35" xlink:to="loc_moh_VirginiaDepartmentOfMedicalAssistanceServiceMember_461cd3e9-acb2-4696-a545-9f023399beec" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_NebraskaDepartmentOfHealthAndHumanServicesMember_463cddf9-b6e4-4a25-8a53-1edc70b40c9e" xlink:href="moh-20240331.xsd#moh_NebraskaDepartmentOfHealthAndHumanServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_59bacb19-8e87-4dfa-9a6d-73a6f8605c35" xlink:to="loc_moh_NebraskaDepartmentOfHealthAndHumanServicesMember_463cddf9-b6e4-4a25-8a53-1edc70b40c9e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_4976d50f-74bf-462f-a798-89eff375f2f0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_dda15bf2-6f50-447e-8cb2-349b713ac633" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_4976d50f-74bf-462f-a798-89eff375f2f0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_4976d50f-74bf-462f-a798-89eff375f2f0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_4976d50f-74bf-462f-a798-89eff375f2f0" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_4976d50f-74bf-462f-a798-89eff375f2f0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_a044669f-7c3d-4517-8712-f96adb16c3ba" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_4976d50f-74bf-462f-a798-89eff375f2f0" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_a044669f-7c3d-4517-8712-f96adb16c3ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_25272e59-2b70-44b8-be5a-d2108ff5feb7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_a044669f-7c3d-4517-8712-f96adb16c3ba" xlink:to="loc_us-gaap_SubsequentEventMember_25272e59-2b70-44b8-be5a-d2108ff5feb7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_051b52df-342d-43ef-af51-33b49122ff34" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_37448f13-ae2c-4b74-9783-b94fd4d0e28f" xlink:to="loc_us-gaap_NumberOfReportableSegments_051b52df-342d-43ef-af51-33b49122ff34" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_NumberOfMembersEligibleForGovernmentSponsoredHealthcarePrograms_717255e8-4214-4a92-a04e-2f31d262c9a6" xlink:href="moh-20240331.xsd#moh_NumberOfMembersEligibleForGovernmentSponsoredHealthcarePrograms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_37448f13-ae2c-4b74-9783-b94fd4d0e28f" xlink:to="loc_moh_NumberOfMembersEligibleForGovernmentSponsoredHealthcarePrograms_717255e8-4214-4a92-a04e-2f31d262c9a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_NumberOfStatesWithGovernmentSponsoredHealthcarePrograms_d1855cb3-26d3-4664-a3f6-fc2c27780d36" xlink:href="moh-20240331.xsd#moh_NumberOfStatesWithGovernmentSponsoredHealthcarePrograms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_37448f13-ae2c-4b74-9783-b94fd4d0e28f" xlink:to="loc_moh_NumberOfStatesWithGovernmentSponsoredHealthcarePrograms_d1855cb3-26d3-4664-a3f6-fc2c27780d36" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_HealthPlanContractTerm_f006fce2-51ec-4a80-be89-7e25139e86a0" xlink:href="moh-20240331.xsd#moh_HealthPlanContractTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_37448f13-ae2c-4b74-9783-b94fd4d0e28f" xlink:to="loc_moh_HealthPlanContractTerm_f006fce2-51ec-4a80-be89-7e25139e86a0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_ContractAwardNumberOfServiceRegions_7ddee0f9-93ce-451c-bee7-4c16a9470394" xlink:href="moh-20240331.xsd#moh_ContractAwardNumberOfServiceRegions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_37448f13-ae2c-4b74-9783-b94fd4d0e28f" xlink:to="loc_moh_ContractAwardNumberOfServiceRegions_7ddee0f9-93ce-451c-bee7-4c16a9470394" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_HealthPlanNumberOfExtensionOptions_a8efdc68-96ec-4ff5-80fe-e15d10646ba6" xlink:href="moh-20240331.xsd#moh_HealthPlanNumberOfExtensionOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_37448f13-ae2c-4b74-9783-b94fd4d0e28f" xlink:to="loc_moh_HealthPlanNumberOfExtensionOptions_a8efdc68-96ec-4ff5-80fe-e15d10646ba6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_HealthPlanExtensionOptionPeriod_219d2962-3b62-4564-a204-9e779610ec2c" xlink:href="moh-20240331.xsd#moh_HealthPlanExtensionOptionPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_37448f13-ae2c-4b74-9783-b94fd4d0e28f" xlink:to="loc_moh_HealthPlanExtensionOptionPeriod_219d2962-3b62-4564-a204-9e779610ec2c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_bb0d20ee-fbb0-41d0-a12b-0a677652ca7e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_37448f13-ae2c-4b74-9783-b94fd4d0e28f" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_bb0d20ee-fbb0-41d0-a12b-0a677652ca7e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_BusinessCombinationNumberOfManagedLongTermServicesAndSupportMembers_5f547331-7c30-49cd-9fd7-4f56b2b8e96e" xlink:href="moh-20240331.xsd#moh_BusinessCombinationNumberOfManagedLongTermServicesAndSupportMembers"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_37448f13-ae2c-4b74-9783-b94fd4d0e28f" xlink:to="loc_moh_BusinessCombinationNumberOfManagedLongTermServicesAndSupportMembers_5f547331-7c30-49cd-9fd7-4f56b2b8e96e" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/SignificantAccountingPoliciesReceivablesDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#SignificantAccountingPoliciesReceivablesDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/SignificantAccountingPoliciesReceivablesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_19e7f4dc-2f91-4ead-9b8b-802c2c3a511d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_ce28cd1d-8002-4874-9f65-8ed0470976f4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_19e7f4dc-2f91-4ead-9b8b-802c2c3a511d" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_ce28cd1d-8002-4874-9f65-8ed0470976f4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_5dce58ab-7277-4f1e-b5b9-9c54af3646c9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_ce28cd1d-8002-4874-9f65-8ed0470976f4" xlink:to="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_5dce58ab-7277-4f1e-b5b9-9c54af3646c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableTypeDomain_5dce58ab-7277-4f1e-b5b9-9c54af3646c9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ReceivableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_5dce58ab-7277-4f1e-b5b9-9c54af3646c9" xlink:to="loc_us-gaap_ReceivableTypeDomain_5dce58ab-7277-4f1e-b5b9-9c54af3646c9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableTypeDomain_d30bd15c-d829-444a-bde8-09cde8b255ff" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ReceivableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_5dce58ab-7277-4f1e-b5b9-9c54af3646c9" xlink:to="loc_us-gaap_ReceivableTypeDomain_d30bd15c-d829-444a-bde8-09cde8b255ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_GovernmentReceivablesMember_c86aace8-184c-45f8-905a-082ef82e7ba8" xlink:href="moh-20240331.xsd#moh_GovernmentReceivablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivableTypeDomain_d30bd15c-d829-444a-bde8-09cde8b255ff" xlink:to="loc_moh_GovernmentReceivablesMember_c86aace8-184c-45f8-905a-082ef82e7ba8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_PharmacyRebateReceivablesMember_0ef06ad3-eff5-4172-b09e-8218c3521146" xlink:href="moh-20240331.xsd#moh_PharmacyRebateReceivablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivableTypeDomain_d30bd15c-d829-444a-bde8-09cde8b255ff" xlink:to="loc_moh_PharmacyRebateReceivablesMember_0ef06ad3-eff5-4172-b09e-8218c3521146" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_OtherReceivablesMember_3cb11bc6-a08d-44d1-9d96-3f175911f72b" xlink:href="moh-20240331.xsd#moh_OtherReceivablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivableTypeDomain_d30bd15c-d829-444a-bde8-09cde8b255ff" xlink:to="loc_moh_OtherReceivablesMember_3cb11bc6-a08d-44d1-9d96-3f175911f72b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesNetCurrent_718c41d5-d730-4bae-86f4-1b1e1de8e18a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ReceivablesNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_19e7f4dc-2f91-4ead-9b8b-802c2c3a511d" xlink:to="loc_us-gaap_ReceivablesNetCurrent_718c41d5-d730-4bae-86f4-1b1e1de8e18a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/SignificantAccountingPoliciesNarrativeDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#SignificantAccountingPoliciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/SignificantAccountingPoliciesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_moh_ScheduleOfPremiumRevenueByHealthPlanTypeLineItems_d1bd13bb-9731-4a51-8510-0d7ca5f3ad99" xlink:href="moh-20240331.xsd#moh_ScheduleOfPremiumRevenueByHealthPlanTypeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_ScheduleOfPremiumRevenueByHealthPlanTypeTable_54d7c451-76bf-4f4e-a452-27baa7690b61" xlink:href="moh-20240331.xsd#moh_ScheduleOfPremiumRevenueByHealthPlanTypeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_moh_ScheduleOfPremiumRevenueByHealthPlanTypeLineItems_d1bd13bb-9731-4a51-8510-0d7ca5f3ad99" xlink:to="loc_moh_ScheduleOfPremiumRevenueByHealthPlanTypeTable_54d7c451-76bf-4f4e-a452-27baa7690b61" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_51bd17e8-cb7e-4d5e-bee5-1d9524003925" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_moh_ScheduleOfPremiumRevenueByHealthPlanTypeTable_54d7c451-76bf-4f4e-a452-27baa7690b61" xlink:to="loc_us-gaap_FinancialInstrumentAxis_51bd17e8-cb7e-4d5e-bee5-1d9524003925" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_51bd17e8-cb7e-4d5e-bee5-1d9524003925_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_51bd17e8-cb7e-4d5e-bee5-1d9524003925" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_51bd17e8-cb7e-4d5e-bee5-1d9524003925_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_8408927f-b339-4b19-bb92-a289d5ac0e46" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_51bd17e8-cb7e-4d5e-bee5-1d9524003925" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_8408927f-b339-4b19-bb92-a289d5ac0e46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_StructuredSecuritiesMember_eacd523f-1745-4a6b-a400-5a40bc0b6423" xlink:href="moh-20240331.xsd#moh_StructuredSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_8408927f-b339-4b19-bb92-a289d5ac0e46" xlink:to="loc_moh_StructuredSecuritiesMember_eacd523f-1745-4a6b-a400-5a40bc0b6423" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_AmountsDueToGovernmentAgenciesRiskAdjustmentAndPartDRiskSharing_98552da4-32ca-4b83-834d-7854508ef37f" xlink:href="moh-20240331.xsd#moh_AmountsDueToGovernmentAgenciesRiskAdjustmentAndPartDRiskSharing"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_moh_ScheduleOfPremiumRevenueByHealthPlanTypeLineItems_d1bd13bb-9731-4a51-8510-0d7ca5f3ad99" xlink:to="loc_moh_AmountsDueToGovernmentAgenciesRiskAdjustmentAndPartDRiskSharing_98552da4-32ca-4b83-834d-7854508ef37f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_AffordableCareActPremiumStabilizationProgramRiskAdjustmentPayable_36066f48-8af8-458e-8418-8b00645fa27b" xlink:href="moh-20240331.xsd#moh_AffordableCareActPremiumStabilizationProgramRiskAdjustmentPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_moh_ScheduleOfPremiumRevenueByHealthPlanTypeLineItems_d1bd13bb-9731-4a51-8510-0d7ca5f3ad99" xlink:to="loc_moh_AffordableCareActPremiumStabilizationProgramRiskAdjustmentPayable_36066f48-8af8-458e-8418-8b00645fa27b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_AffordableCareActPremiumStabilizationProgramRiskAdjustmentReceivable_c2dd23b8-6b17-4978-a2f6-960841c81464" xlink:href="moh-20240331.xsd#moh_AffordableCareActPremiumStabilizationProgramRiskAdjustmentReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_moh_ScheduleOfPremiumRevenueByHealthPlanTypeLineItems_d1bd13bb-9731-4a51-8510-0d7ca5f3ad99" xlink:to="loc_moh_AffordableCareActPremiumStabilizationProgramRiskAdjustmentReceivable_c2dd23b8-6b17-4978-a2f6-960841c81464" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_AffordableCareActPremiumStabilizationProgramRiskAdjustmentNetReceivable_898d0749-2b63-41cf-b8fb-57df83bcc1fb" xlink:href="moh-20240331.xsd#moh_AffordableCareActPremiumStabilizationProgramRiskAdjustmentNetReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_moh_ScheduleOfPremiumRevenueByHealthPlanTypeLineItems_d1bd13bb-9731-4a51-8510-0d7ca5f3ad99" xlink:to="loc_moh_AffordableCareActPremiumStabilizationProgramRiskAdjustmentNetReceivable_898d0749-2b63-41cf-b8fb-57df83bcc1fb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_InvestmentsMaturityPeriod_d3bc815e-80b2-43e2-af32-a1795d467156" xlink:href="moh-20240331.xsd#moh_InvestmentsMaturityPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_moh_ScheduleOfPremiumRevenueByHealthPlanTypeLineItems_d1bd13bb-9731-4a51-8510-0d7ca5f3ad99" xlink:to="loc_moh_InvestmentsMaturityPeriod_d3bc815e-80b2-43e2-af32-a1795d467156" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_InvestmentsAverageMaturityPeriod_5a77fde6-22a9-44a6-915b-180cd1625ccb" xlink:href="moh-20240331.xsd#moh_InvestmentsAverageMaturityPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_moh_ScheduleOfPremiumRevenueByHealthPlanTypeLineItems_d1bd13bb-9731-4a51-8510-0d7ca5f3ad99" xlink:to="loc_moh_InvestmentsAverageMaturityPeriod_5a77fde6-22a9-44a6-915b-180cd1625ccb" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/BusinessCombinationsNarrativeDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#BusinessCombinationsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/BusinessCombinationsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionContingentConsiderationLineItems_ce7b5953-7615-428a-99ae-9af8ee02eb6e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionContingentConsiderationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable_8e463c54-3f8c-451e-b236-9d655b9efced" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionContingentConsiderationLineItems_ce7b5953-7615-428a-99ae-9af8ee02eb6e" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable_8e463c54-3f8c-451e-b236-9d655b9efced" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_82e5872e-19af-4d67-a526-d70c277d5545" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable_8e463c54-3f8c-451e-b236-9d655b9efced" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_82e5872e-19af-4d67-a526-d70c277d5545" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_82e5872e-19af-4d67-a526-d70c277d5545_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_82e5872e-19af-4d67-a526-d70c277d5545" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_82e5872e-19af-4d67-a526-d70c277d5545_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_cb234018-90cf-440f-b877-a77eb7e4164c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_82e5872e-19af-4d67-a526-d70c277d5545" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_cb234018-90cf-440f-b877-a77eb7e4164c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_BrightHealthMedicareMember_de9fd7cf-8c6f-4490-8502-6e73074c658c" xlink:href="moh-20240331.xsd#moh_BrightHealthMedicareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_cb234018-90cf-440f-b877-a77eb7e4164c" xlink:to="loc_moh_BrightHealthMedicareMember_de9fd7cf-8c6f-4490-8502-6e73074c658c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_f7af0974-075d-4533-baea-2b6cf8b1a8e6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionContingentConsiderationLineItems_ce7b5953-7615-428a-99ae-9af8ee02eb6e" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_f7af0974-075d-4533-baea-2b6cf8b1a8e6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquisitionCosts_79555e6d-0283-4f00-93e6-6283abd7642c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AcquisitionCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionContingentConsiderationLineItems_ce7b5953-7615-428a-99ae-9af8ee02eb6e" xlink:to="loc_us-gaap_AcquisitionCosts_79555e6d-0283-4f00-93e6-6283abd7642c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_b37f1a80-c0c2-49c1-b0c4-8164fff5d5a9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionContingentConsiderationLineItems_ce7b5953-7615-428a-99ae-9af8ee02eb6e" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_b37f1a80-c0c2-49c1-b0c4-8164fff5d5a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_897bfaea-67d5-4e5d-b34a-b6dadb3b6f0d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionContingentConsiderationLineItems_ce7b5953-7615-428a-99ae-9af8ee02eb6e" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_897bfaea-67d5-4e5d-b34a-b6dadb3b6f0d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EscrowDeposit_1eb0cde3-35b8-41aa-bbe2-446be80e3b2c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EscrowDeposit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionContingentConsiderationLineItems_ce7b5953-7615-428a-99ae-9af8ee02eb6e" xlink:to="loc_us-gaap_EscrowDeposit_1eb0cde3-35b8-41aa-bbe2-446be80e3b2c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_bca075e3-c82e-4cf6-8856-1297c6615e79" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationAcquiredReceivablesFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionContingentConsiderationLineItems_ce7b5953-7615-428a-99ae-9af8ee02eb6e" xlink:to="loc_us-gaap_BusinessCombinationAcquiredReceivablesFairValue_bca075e3-c82e-4cf6-8856-1297c6615e79" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/BusinessCombinationsSummaryofFairValueConsiderationDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#BusinessCombinationsSummaryofFairValueConsiderationDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/BusinessCombinationsSummaryofFairValueConsiderationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems_d1ffba9a-ff7d-463a-9420-9e46fe771a59" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTable_1b5186e4-47a6-4a64-b3ce-66176e7e1852" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems_d1ffba9a-ff7d-463a-9420-9e46fe771a59" xlink:to="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTable_1b5186e4-47a6-4a64-b3ce-66176e7e1852" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_f6abc316-d4b3-452f-a587-6cebd834da55" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTable_1b5186e4-47a6-4a64-b3ce-66176e7e1852" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_f6abc316-d4b3-452f-a587-6cebd834da55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_f6abc316-d4b3-452f-a587-6cebd834da55_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_f6abc316-d4b3-452f-a587-6cebd834da55" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_f6abc316-d4b3-452f-a587-6cebd834da55_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b2dbdedb-9899-41dd-bc05-a70ae24f2746" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_f6abc316-d4b3-452f-a587-6cebd834da55" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b2dbdedb-9899-41dd-bc05-a70ae24f2746" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_BrightHealthMedicareMember_7d8c54e9-ef94-4faf-ab8d-8ca57fa5c8d0" xlink:href="moh-20240331.xsd#moh_BrightHealthMedicareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b2dbdedb-9899-41dd-bc05-a70ae24f2746" xlink:to="loc_moh_BrightHealthMedicareMember_7d8c54e9-ef94-4faf-ab8d-8ca57fa5c8d0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_5a941fd1-4eaa-4df5-b1fa-bc3bd27c5656" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems_d1ffba9a-ff7d-463a-9420-9e46fe771a59" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_5a941fd1-4eaa-4df5-b1fa-bc3bd27c5656" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_3e465eef-74bb-4e7a-99a9-9aa2a9d3d09a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems_d1ffba9a-ff7d-463a-9420-9e46fe771a59" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_3e465eef-74bb-4e7a-99a9-9aa2a9d3d09a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_1d98c960-3ca5-4199-ae34-157240570c9a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems_d1ffba9a-ff7d-463a-9420-9e46fe771a59" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_1d98c960-3ca5-4199-ae34-157240570c9a" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/BusinessCombinationsScheduleofTheProvisionalFairValuesAssignedToAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#BusinessCombinationsScheduleofTheProvisionalFairValuesAssignedToAssetsAcquiredandLiabilitiesAssumedDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/BusinessCombinationsScheduleofTheProvisionalFairValuesAssignedToAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems_f97226a4-75a2-43fd-a2a2-3b2baaa72020" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTable_a3acd0ff-31b2-4e3a-a575-3f060e60aa32" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems_f97226a4-75a2-43fd-a2a2-3b2baaa72020" xlink:to="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTable_a3acd0ff-31b2-4e3a-a575-3f060e60aa32" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_8b1588c4-c38e-48f0-98c9-fd41aed2d132" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsTable_a3acd0ff-31b2-4e3a-a575-3f060e60aa32" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_8b1588c4-c38e-48f0-98c9-fd41aed2d132" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8b1588c4-c38e-48f0-98c9-fd41aed2d132_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_8b1588c4-c38e-48f0-98c9-fd41aed2d132" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_8b1588c4-c38e-48f0-98c9-fd41aed2d132_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1e6eccd6-2d5f-4716-be5a-481141050d6a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_8b1588c4-c38e-48f0-98c9-fd41aed2d132" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1e6eccd6-2d5f-4716-be5a-481141050d6a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_BrightHealthMedicareMember_a527d698-81d4-4ae2-a6fb-251d835605e8" xlink:href="moh-20240331.xsd#moh_BrightHealthMedicareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1e6eccd6-2d5f-4716-be5a-481141050d6a" xlink:to="loc_moh_BrightHealthMedicareMember_a527d698-81d4-4ae2-a6fb-251d835605e8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_46eb74bb-4d21-46c1-8085-b1066d007549" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems_f97226a4-75a2-43fd-a2a2-3b2baaa72020" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_46eb74bb-4d21-46c1-8085-b1066d007549" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_0797cfe1-b09a-4bee-9567-112a52d5a004" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_46eb74bb-4d21-46c1-8085-b1066d007549" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_0797cfe1-b09a-4bee-9567-112a52d5a004" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_6a6da87c-c306-49c0-b9d0-5508a85acf40" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_46eb74bb-4d21-46c1-8085-b1066d007549" xlink:to="loc_us-gaap_Goodwill_6a6da87c-c306-49c0-b9d0-5508a85acf40" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_ee7e5639-843b-43e0-97a0-6037f7cdb32b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_46eb74bb-4d21-46c1-8085-b1066d007549" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_ee7e5639-843b-43e0-97a0-6037f7cdb32b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_e5b06904-ea28-4985-aa12-ab19e876ad64" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_46eb74bb-4d21-46c1-8085-b1066d007549" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_e5b06904-ea28-4985-aa12-ab19e876ad64" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_72e0a6d4-35d2-4a5f-8f25-05206e02d09e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems_f97226a4-75a2-43fd-a2a2-3b2baaa72020" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_72e0a6d4-35d2-4a5f-8f25-05206e02d09e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesMedicalClaimsAndBenefitsPayable_3a9258ac-8638-498a-936b-7fa9be759d98" xlink:href="moh-20240331.xsd#moh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesMedicalClaimsAndBenefitsPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_72e0a6d4-35d2-4a5f-8f25-05206e02d09e" xlink:to="loc_moh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesMedicalClaimsAndBenefitsPayable_3a9258ac-8638-498a-936b-7fa9be759d98" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAmountsDueGovernmentAgencies_0e1e2b5c-2f09-44c4-99ce-c59cdbb5407e" xlink:href="moh-20240331.xsd#moh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAmountsDueGovernmentAgencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_72e0a6d4-35d2-4a5f-8f25-05206e02d09e" xlink:to="loc_moh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAmountsDueGovernmentAgencies_0e1e2b5c-2f09-44c4-99ce-c59cdbb5407e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccountsPayableAccruedAndOtherNoncurrentLiabilities_576119a3-6192-4244-8549-913ea4e8bef5" xlink:href="moh-20240331.xsd#moh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccountsPayableAccruedAndOtherNoncurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_72e0a6d4-35d2-4a5f-8f25-05206e02d09e" xlink:to="loc_moh_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccountsPayableAccruedAndOtherNoncurrentLiabilities_576119a3-6192-4244-8549-913ea4e8bef5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_021a0f82-99ba-45a0-80d3-1a647d7a3a04" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsLineItems_f97226a4-75a2-43fd-a2a2-3b2baaa72020" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_021a0f82-99ba-45a0-80d3-1a647d7a3a04" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/BusinessCombinationsIntangibleAssetsAcquiredDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#BusinessCombinationsIntangibleAssetsAcquiredDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/BusinessCombinationsIntangibleAssetsAcquiredDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_fe2f519a-768c-4917-8a11-841608983a5d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_14553dc6-ef95-466f-9445-aa7f70813fcf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_fe2f519a-768c-4917-8a11-841608983a5d" xlink:to="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_14553dc6-ef95-466f-9445-aa7f70813fcf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_158ee95d-9bb5-4335-bf8b-d4669e7bc060" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_14553dc6-ef95-466f-9445-aa7f70813fcf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_158ee95d-9bb5-4335-bf8b-d4669e7bc060" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_158ee95d-9bb5-4335-bf8b-d4669e7bc060_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_158ee95d-9bb5-4335-bf8b-d4669e7bc060" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_158ee95d-9bb5-4335-bf8b-d4669e7bc060_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_102eb483-af1e-4803-9ea1-d616d5efa2e1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_158ee95d-9bb5-4335-bf8b-d4669e7bc060" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_102eb483-af1e-4803-9ea1-d616d5efa2e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualRightsMember_2ef925eb-e075-45cd-9380-89ce126645b7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ContractualRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_102eb483-af1e-4803-9ea1-d616d5efa2e1" xlink:to="loc_us-gaap_ContractualRightsMember_2ef925eb-e075-45cd-9380-89ce126645b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_13bb043c-6686-4ca3-8cf9-6fec627ea108" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_102eb483-af1e-4803-9ea1-d616d5efa2e1" xlink:to="loc_us-gaap_TradeNamesMember_13bb043c-6686-4ca3-8cf9-6fec627ea108" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_ProviderNetworkMember_620276a0-28fe-44f0-b1bb-e7263b37455b" xlink:href="moh-20240331.xsd#moh_ProviderNetworkMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_102eb483-af1e-4803-9ea1-d616d5efa2e1" xlink:to="loc_moh_ProviderNetworkMember_620276a0-28fe-44f0-b1bb-e7263b37455b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_9422c1f3-51df-4744-8dc4-55441996f935" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_14553dc6-ef95-466f-9445-aa7f70813fcf" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_9422c1f3-51df-4744-8dc4-55441996f935" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9422c1f3-51df-4744-8dc4-55441996f935_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9422c1f3-51df-4744-8dc4-55441996f935" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9422c1f3-51df-4744-8dc4-55441996f935_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4853517e-a20a-4b2d-b121-19783e963ea9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9422c1f3-51df-4744-8dc4-55441996f935" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4853517e-a20a-4b2d-b121-19783e963ea9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_BrightHealthMedicareMember_fdca23fd-cf8d-4ffc-beb0-a62688fdb237" xlink:href="moh-20240331.xsd#moh_BrightHealthMedicareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_4853517e-a20a-4b2d-b121-19783e963ea9" xlink:to="loc_moh_BrightHealthMedicareMember_fdca23fd-cf8d-4ffc-beb0-a62688fdb237" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_9c65eb35-88b8-4e94-9225-c3fe1a8a20a9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_fe2f519a-768c-4917-8a11-841608983a5d" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_9c65eb35-88b8-4e94-9225-c3fe1a8a20a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_a0e1ddfb-29cd-4e96-95fc-b70429f3d374" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_fe2f519a-768c-4917-8a11-841608983a5d" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_a0e1ddfb-29cd-4e96-95fc-b70429f3d374" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_c41fe728-635d-489b-9cba-2a0196d425f6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_fe2f519a-768c-4917-8a11-841608983a5d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_c41fe728-635d-489b-9cba-2a0196d425f6" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/FairValueMeasurementsFinancialInstrumentsonaRecurringBasisDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#FairValueMeasurementsFinancialInstrumentsonaRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/FairValueMeasurementsFinancialInstrumentsonaRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_dcdaf5ec-1342-406f-bfe4-f8b63ebde7f7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_b46fc585-737c-4850-9cd5-a1ee94e04641" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_dcdaf5ec-1342-406f-bfe4-f8b63ebde7f7" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_b46fc585-737c-4850-9cd5-a1ee94e04641" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_19bfc62b-c294-41a4-9ae0-45238725b38f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_b46fc585-737c-4850-9cd5-a1ee94e04641" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_19bfc62b-c294-41a4-9ae0-45238725b38f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_19bfc62b-c294-41a4-9ae0-45238725b38f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_19bfc62b-c294-41a4-9ae0-45238725b38f" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_19bfc62b-c294-41a4-9ae0-45238725b38f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_40828cb0-36c3-4698-920f-5ef5ddda6959" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_19bfc62b-c294-41a4-9ae0-45238725b38f" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_40828cb0-36c3-4698-920f-5ef5ddda6959" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_979835f3-967c-42f1-b238-cee6add7fb20" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_40828cb0-36c3-4698-920f-5ef5ddda6959" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_979835f3-967c-42f1-b238-cee6add7fb20" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_7481457f-f1aa-4550-aeca-4d5d163d7b3f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_40828cb0-36c3-4698-920f-5ef5ddda6959" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_7481457f-f1aa-4550-aeca-4d5d163d7b3f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_07348796-3260-4237-b782-866a74f014e4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_40828cb0-36c3-4698-920f-5ef5ddda6959" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_07348796-3260-4237-b782-866a74f014e4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_5e3ef55e-60b9-4a94-ac84-e59396e22560" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_b46fc585-737c-4850-9cd5-a1ee94e04641" xlink:to="loc_us-gaap_FinancialInstrumentAxis_5e3ef55e-60b9-4a94-ac84-e59396e22560" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_5e3ef55e-60b9-4a94-ac84-e59396e22560_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_5e3ef55e-60b9-4a94-ac84-e59396e22560" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_5e3ef55e-60b9-4a94-ac84-e59396e22560_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e977c408-efe7-4f7c-9db8-8629f8589957" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_5e3ef55e-60b9-4a94-ac84-e59396e22560" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e977c408-efe7-4f7c-9db8-8629f8589957" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_86c1addc-3e34-469f-82ef-11c2bc5a4637" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CorporateDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e977c408-efe7-4f7c-9db8-8629f8589957" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_86c1addc-3e34-469f-82ef-11c2bc5a4637" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_fa982901-3603-4f49-a1bd-f3c2bc9e0820" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CommercialMortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e977c408-efe7-4f7c-9db8-8629f8589957" xlink:to="loc_us-gaap_CommercialMortgageBackedSecuritiesMember_fa982901-3603-4f49-a1bd-f3c2bc9e0820" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetBackedSecuritiesMember_b0ab9174-64d6-4d9b-9bfe-57c359288071" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e977c408-efe7-4f7c-9db8-8629f8589957" xlink:to="loc_us-gaap_AssetBackedSecuritiesMember_b0ab9174-64d6-4d9b-9bfe-57c359288071" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MunicipalSecuritiesMember_d55c340d-6f68-4a51-b1cd-c8029e42c2f7" xlink:href="moh-20240331.xsd#moh_MunicipalSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e977c408-efe7-4f7c-9db8-8629f8589957" xlink:to="loc_moh_MunicipalSecuritiesMember_d55c340d-6f68-4a51-b1cd-c8029e42c2f7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasuryNotesSecuritiesMember_93e12ac7-4125-4845-a84e-c5bbd7e6c444" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_USTreasuryNotesSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e977c408-efe7-4f7c-9db8-8629f8589957" xlink:to="loc_us-gaap_USTreasuryNotesSecuritiesMember_93e12ac7-4125-4845-a84e-c5bbd7e6c444" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_OtherSecuritiesMember_5f408999-e8db-4307-a2a7-0653062e72dd" xlink:href="moh-20240331.xsd#moh_OtherSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_e977c408-efe7-4f7c-9db8-8629f8589957" xlink:to="loc_moh_OtherSecuritiesMember_5f408999-e8db-4307-a2a7-0653062e72dd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_e05c00f7-2f5f-4450-90c1-9366c9163eae" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_dcdaf5ec-1342-406f-bfe4-f8b63ebde7f7" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_e05c00f7-2f5f-4450-90c1-9366c9163eae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_103e3f74-d816-4e04-a826-b470675c7557" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_dcdaf5ec-1342-406f-bfe4-f8b63ebde7f7" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_103e3f74-d816-4e04-a826-b470675c7557" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/FairValueMeasurementsLongTermDebtDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#FairValueMeasurementsLongTermDebtDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/FairValueMeasurementsLongTermDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_cd3f2a93-32c5-4c95-a694-8eb78fdf17d1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_c7ecc3ca-6b15-453f-88dd-f7b646c41b78" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_cd3f2a93-32c5-4c95-a694-8eb78fdf17d1" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_c7ecc3ca-6b15-453f-88dd-f7b646c41b78" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_fef989fc-192a-468d-9792-7f6569cbeae8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_c7ecc3ca-6b15-453f-88dd-f7b646c41b78" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_fef989fc-192a-468d-9792-7f6569cbeae8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_fef989fc-192a-468d-9792-7f6569cbeae8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_fef989fc-192a-468d-9792-7f6569cbeae8" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_fef989fc-192a-468d-9792-7f6569cbeae8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_3b23f1a4-5e0b-4d98-9d66-62101e526d7a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_fef989fc-192a-468d-9792-7f6569cbeae8" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_3b23f1a4-5e0b-4d98-9d66-62101e526d7a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_88a4b672-14a3-40ec-a816-ccd20de058f4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_3b23f1a4-5e0b-4d98-9d66-62101e526d7a" xlink:to="loc_us-gaap_SeniorNotesMember_88a4b672-14a3-40ec-a816-ccd20de058f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_8bc2cfff-5862-4124-819c-d48cef31fd27" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_c7ecc3ca-6b15-453f-88dd-f7b646c41b78" xlink:to="loc_us-gaap_DebtInstrumentAxis_8bc2cfff-5862-4124-819c-d48cef31fd27" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_8bc2cfff-5862-4124-819c-d48cef31fd27_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_8bc2cfff-5862-4124-819c-d48cef31fd27" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_8bc2cfff-5862-4124-819c-d48cef31fd27_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_0b6ccb0e-7e25-4665-b3ba-f16ec49f1c25" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_8bc2cfff-5862-4124-819c-d48cef31fd27" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_0b6ccb0e-7e25-4665-b3ba-f16ec49f1c25" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_A4375SeniorNotesMember_df061a0b-9c07-45a8-9f6a-6b78d0d1b16c" xlink:href="moh-20240331.xsd#moh_A4375SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_0b6ccb0e-7e25-4665-b3ba-f16ec49f1c25" xlink:to="loc_moh_A4375SeniorNotesMember_df061a0b-9c07-45a8-9f6a-6b78d0d1b16c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_ThreePointEightSevenFivePercentSeniorNotesMember_39f63808-d791-40f8-a5bf-0c87a54894c7" xlink:href="moh-20240331.xsd#moh_ThreePointEightSevenFivePercentSeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_0b6ccb0e-7e25-4665-b3ba-f16ec49f1c25" xlink:to="loc_moh_ThreePointEightSevenFivePercentSeniorNotesMember_39f63808-d791-40f8-a5bf-0c87a54894c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_A3875SeniorNotesMember_8d9c0f0d-f3d9-4776-b42a-519f9169c1a9" xlink:href="moh-20240331.xsd#moh_A3875SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_0b6ccb0e-7e25-4665-b3ba-f16ec49f1c25" xlink:to="loc_moh_A3875SeniorNotesMember_8d9c0f0d-f3d9-4776-b42a-519f9169c1a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_bbe1f2f7-ef4f-430a-a4f8-78473cf090f5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_c7ecc3ca-6b15-453f-88dd-f7b646c41b78" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_bbe1f2f7-ef4f-430a-a4f8-78473cf090f5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_bbe1f2f7-ef4f-430a-a4f8-78473cf090f5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_bbe1f2f7-ef4f-430a-a4f8-78473cf090f5" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_bbe1f2f7-ef4f-430a-a4f8-78473cf090f5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_88b55120-b434-4c32-85da-4d8786cc6543" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_bbe1f2f7-ef4f-430a-a4f8-78473cf090f5" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_88b55120-b434-4c32-85da-4d8786cc6543" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_6c08610a-b157-45b2-a4e7-aa8d6d170459" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_88b55120-b434-4c32-85da-4d8786cc6543" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_6c08610a-b157-45b2-a4e7-aa8d6d170459" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_2d419241-ef1d-413d-8589-5e9342821104" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_6c08610a-b157-45b2-a4e7-aa8d6d170459" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_2d419241-ef1d-413d-8589-5e9342821104" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_7a17aa4f-606c-48dc-970d-bd374f73c383" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_6c08610a-b157-45b2-a4e7-aa8d6d170459" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_7a17aa4f-606c-48dc-970d-bd374f73c383" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_c10f03ae-af12-4d86-8c51-e2baf26be5d6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_cd3f2a93-32c5-4c95-a694-8eb78fdf17d1" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_c10f03ae-af12-4d86-8c51-e2baf26be5d6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFairValue_a934b3d6-14e8-46a8-865c-759c5ae66a0f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_cd3f2a93-32c5-4c95-a694-8eb78fdf17d1" xlink:to="loc_us-gaap_DebtInstrumentFairValue_a934b3d6-14e8-46a8-865c-759c5ae66a0f" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/InvestmentsSummaryofInvestmentsDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#InvestmentsSummaryofInvestmentsDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/InvestmentsSummaryofInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_74990fce-3003-4302-be70-2e7d2d7e0c2b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_7e71959e-6d18-41f9-b299-0f4f16c2a8ea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_74990fce-3003-4302-be70-2e7d2d7e0c2b" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_7e71959e-6d18-41f9-b299-0f4f16c2a8ea" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_67347d99-9a9f-4ee6-9bb6-c24a42326f5b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_7e71959e-6d18-41f9-b299-0f4f16c2a8ea" xlink:to="loc_us-gaap_FinancialInstrumentAxis_67347d99-9a9f-4ee6-9bb6-c24a42326f5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_67347d99-9a9f-4ee6-9bb6-c24a42326f5b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_67347d99-9a9f-4ee6-9bb6-c24a42326f5b" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_67347d99-9a9f-4ee6-9bb6-c24a42326f5b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0cf201f1-b3d1-4459-bdea-e87c5746c12b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_67347d99-9a9f-4ee6-9bb6-c24a42326f5b" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0cf201f1-b3d1-4459-bdea-e87c5746c12b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_4de0c28a-e34d-47e9-aa78-37818c84f1f5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CorporateDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0cf201f1-b3d1-4459-bdea-e87c5746c12b" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_4de0c28a-e34d-47e9-aa78-37818c84f1f5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MortgageBackedSecuritiesMember_6a98ef61-0d3b-4347-b3c3-3cfaf214bf8e" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0cf201f1-b3d1-4459-bdea-e87c5746c12b" xlink:to="loc_us-gaap_MortgageBackedSecuritiesMember_6a98ef61-0d3b-4347-b3c3-3cfaf214bf8e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetBackedSecuritiesMember_f1ce0790-80db-4e06-8589-602a40f8faca" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0cf201f1-b3d1-4459-bdea-e87c5746c12b" xlink:to="loc_us-gaap_AssetBackedSecuritiesMember_f1ce0790-80db-4e06-8589-602a40f8faca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MunicipalSecuritiesMember_e23616b1-30bf-4e76-9df4-bcc6e28978a0" xlink:href="moh-20240331.xsd#moh_MunicipalSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0cf201f1-b3d1-4459-bdea-e87c5746c12b" xlink:to="loc_moh_MunicipalSecuritiesMember_e23616b1-30bf-4e76-9df4-bcc6e28978a0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasuryNotesSecuritiesMember_4942ef56-c59a-4865-9493-2561cd6905c5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_USTreasuryNotesSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0cf201f1-b3d1-4459-bdea-e87c5746c12b" xlink:to="loc_us-gaap_USTreasuryNotesSecuritiesMember_4942ef56-c59a-4865-9493-2561cd6905c5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_OtherSecuritiesMember_578a0eac-5165-4e54-9460-12bc59f633d6" xlink:href="moh-20240331.xsd#moh_OtherSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0cf201f1-b3d1-4459-bdea-e87c5746c12b" xlink:to="loc_moh_OtherSecuritiesMember_578a0eac-5165-4e54-9460-12bc59f633d6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_a8c72aeb-25c2-4058-93c9-b74ce0b4c2cf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_74990fce-3003-4302-be70-2e7d2d7e0c2b" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_a8c72aeb-25c2-4058-93c9-b74ce0b4c2cf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_891ff932-9701-47fe-b2bf-55d6dfd45cef" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_74990fce-3003-4302-be70-2e7d2d7e0c2b" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_891ff932-9701-47fe-b2bf-55d6dfd45cef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_49c02b72-613b-4934-ab8a-e8f39e07f636" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_74990fce-3003-4302-be70-2e7d2d7e0c2b" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_49c02b72-613b-4934-ab8a-e8f39e07f636" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_e30583dd-ca0f-43ec-8828-668d7cff73d4" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_74990fce-3003-4302-be70-2e7d2d7e0c2b" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_e30583dd-ca0f-43ec-8828-668d7cff73d4" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/InvestmentsAvailableforSaleInvestmentsDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#InvestmentsAvailableforSaleInvestmentsDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/InvestmentsAvailableforSaleInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_7d81afcb-dc55-4a49-9793-699b770fcaf6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_c5d43d71-4326-4496-8fec-024e1756eaaa" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_7d81afcb-dc55-4a49-9793-699b770fcaf6" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_c5d43d71-4326-4496-8fec-024e1756eaaa" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_2b5798e0-1768-452f-b3e5-9fc537d13a8a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_c5d43d71-4326-4496-8fec-024e1756eaaa" xlink:to="loc_us-gaap_FinancialInstrumentAxis_2b5798e0-1768-452f-b3e5-9fc537d13a8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_2b5798e0-1768-452f-b3e5-9fc537d13a8a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_2b5798e0-1768-452f-b3e5-9fc537d13a8a" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_2b5798e0-1768-452f-b3e5-9fc537d13a8a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_7a9efabb-3efb-45e8-a39e-20284eb705f2" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_2b5798e0-1768-452f-b3e5-9fc537d13a8a" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_7a9efabb-3efb-45e8-a39e-20284eb705f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_59c37818-7027-4db8-b57d-4c228f7f4331" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CorporateDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_7a9efabb-3efb-45e8-a39e-20284eb705f2" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_59c37818-7027-4db8-b57d-4c228f7f4331" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MortgageBackedSecuritiesMember_f2741358-4c64-460b-9c9f-c7105141f1fc" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MortgageBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_7a9efabb-3efb-45e8-a39e-20284eb705f2" xlink:to="loc_us-gaap_MortgageBackedSecuritiesMember_f2741358-4c64-460b-9c9f-c7105141f1fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetBackedSecuritiesMember_a139056c-94db-4a49-a20d-77091ac07ac0" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_AssetBackedSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_7a9efabb-3efb-45e8-a39e-20284eb705f2" xlink:to="loc_us-gaap_AssetBackedSecuritiesMember_a139056c-94db-4a49-a20d-77091ac07ac0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MunicipalSecuritiesMember_90e6747e-4300-4ef6-a908-168ac448edb2" xlink:href="moh-20240331.xsd#moh_MunicipalSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_7a9efabb-3efb-45e8-a39e-20284eb705f2" xlink:to="loc_moh_MunicipalSecuritiesMember_90e6747e-4300-4ef6-a908-168ac448edb2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasuryNotesSecuritiesMember_275999b8-ea2a-4ab4-8684-e4e8d02f62f6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_USTreasuryNotesSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_7a9efabb-3efb-45e8-a39e-20284eb705f2" xlink:to="loc_us-gaap_USTreasuryNotesSecuritiesMember_275999b8-ea2a-4ab4-8684-e4e8d02f62f6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_OtherSecuritiesMember_10a633ff-aa4c-4193-a0f7-c9e5a76efa3e" xlink:href="moh-20240331.xsd#moh_OtherSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_7a9efabb-3efb-45e8-a39e-20284eb705f2" xlink:to="loc_moh_OtherSecuritiesMember_10a633ff-aa4c-4193-a0f7-c9e5a76efa3e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_567a500d-e3fb-4cdf-9b48-f781214634c3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_7d81afcb-dc55-4a49-9793-699b770fcaf6" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_567a500d-e3fb-4cdf-9b48-f781214634c3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_160fb6b5-e0ec-416d-855f-c3402107c0be" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_7d81afcb-dc55-4a49-9793-699b770fcaf6" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_160fb6b5-e0ec-416d-855f-c3402107c0be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions_c404c873-ea54-4cc3-840b-1a1a04c80272" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_7d81afcb-dc55-4a49-9793-699b770fcaf6" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions_c404c873-ea54-4cc3-840b-1a1a04c80272" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_a6574bcb-adca-4463-9d70-8e664ca3e0b3" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_7d81afcb-dc55-4a49-9793-699b770fcaf6" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_a6574bcb-adca-4463-9d70-8e664ca3e0b3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_0aca8078-ac8c-43bd-a03a-bb8deba0a338" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_7d81afcb-dc55-4a49-9793-699b770fcaf6" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_0aca8078-ac8c-43bd-a03a-bb8deba0a338" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions_b1e0ddbb-0a6a-49df-8953-c937b197621c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_7d81afcb-dc55-4a49-9793-699b770fcaf6" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions_b1e0ddbb-0a6a-49df-8953-c937b197621c" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/MedicalClaimsandBenefitsPayableComponentsofChangeinMedicalClaimsandBenefitsPayableDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#MedicalClaimsandBenefitsPayableComponentsofChangeinMedicalClaimsandBenefitsPayableDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/MedicalClaimsandBenefitsPayableComponentsofChangeinMedicalClaimsandBenefitsPayableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpenseLineItems_033e917f-d598-4472-a4f5-cb7612f87ef8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpenseLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpenseTable_414bba41-c89a-4a4c-b158-42e7e7fce9f9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpenseTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpenseLineItems_033e917f-d598-4472-a4f5-cb7612f87ef8" xlink:to="loc_us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpenseTable_414bba41-c89a-4a4c-b158-42e7e7fce9f9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_157f0ef1-e6c3-49d5-b9ec-f9529e5872ea" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpenseTable_414bba41-c89a-4a4c-b158-42e7e7fce9f9" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_157f0ef1-e6c3-49d5-b9ec-f9529e5872ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_157f0ef1-e6c3-49d5-b9ec-f9529e5872ea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_157f0ef1-e6c3-49d5-b9ec-f9529e5872ea" xlink:to="loc_us-gaap_SegmentDomain_157f0ef1-e6c3-49d5-b9ec-f9529e5872ea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_d8a144d1-ffde-4c20-be03-f6796cc87291" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_157f0ef1-e6c3-49d5-b9ec-f9529e5872ea" xlink:to="loc_us-gaap_SegmentDomain_d8a144d1-ffde-4c20-be03-f6796cc87291" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MedicaidMember_db3045d3-336d-42a3-a956-027bac8a80ae" xlink:href="moh-20240331.xsd#moh_MedicaidMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d8a144d1-ffde-4c20-be03-f6796cc87291" xlink:to="loc_moh_MedicaidMember_db3045d3-336d-42a3-a956-027bac8a80ae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MedicareMember_dd43f898-2200-4d78-8c53-adc46b168493" xlink:href="moh-20240331.xsd#moh_MedicareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d8a144d1-ffde-4c20-be03-f6796cc87291" xlink:to="loc_moh_MedicareMember_dd43f898-2200-4d78-8c53-adc46b168493" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MarketplaceMember_68d92c60-26a1-4953-8008-6b82cf4dff46" xlink:href="moh-20240331.xsd#moh_MarketplaceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d8a144d1-ffde-4c20-be03-f6796cc87291" xlink:to="loc_moh_MarketplaceMember_68d92c60-26a1-4953-8008-6b82cf4dff46" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNetAbstract_46dd5c53-53f6-4112-a752-eb030d80d118" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpenseLineItems_033e917f-d598-4472-a4f5-cb7612f87ef8" xlink:to="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNetAbstract_46dd5c53-53f6-4112-a752-eb030d80d118" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpense_b84cab25-5100-483e-be23-945cd1bc693d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNetAbstract_46dd5c53-53f6-4112-a752-eb030d80d118" xlink:to="loc_us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpense_b84cab25-5100-483e-be23-945cd1bc693d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_ComponentsOfMedicalCareCostsAbstract_cad814ba-a59c-4b41-ae59-03d3ff3e1a53" xlink:href="moh-20240331.xsd#moh_ComponentsOfMedicalCareCostsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNetAbstract_46dd5c53-53f6-4112-a752-eb030d80d118" xlink:to="loc_moh_ComponentsOfMedicalCareCostsAbstract_cad814ba-a59c-4b41-ae59-03d3ff3e1a53" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense_16a6b06a-7a0e-4966-aa65-395798875806" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_moh_ComponentsOfMedicalCareCostsAbstract_cad814ba-a59c-4b41-ae59-03d3ff3e1a53" xlink:to="loc_us-gaap_SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense_16a6b06a-7a0e-4966-aa65-395798875806" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense_78464f64-245d-4a50-9dcf-6aa98f98f202" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_moh_ComponentsOfMedicalCareCostsAbstract_cad814ba-a59c-4b41-ae59-03d3ff3e1a53" xlink:to="loc_us-gaap_SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense_78464f64-245d-4a50-9dcf-6aa98f98f202" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1_2938bb6d-6a3c-44e7-9566-d033e3d84a15" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_moh_ComponentsOfMedicalCareCostsAbstract_cad814ba-a59c-4b41-ae59-03d3ff3e1a53" xlink:to="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1_2938bb6d-6a3c-44e7-9566-d033e3d84a15" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_PaymentsForMedicalCareCostsAbstract_401e1f5c-cf63-4862-a551-d9d58f7b05dc" xlink:href="moh-20240331.xsd#moh_PaymentsForMedicalCareCostsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNetAbstract_46dd5c53-53f6-4112-a752-eb030d80d118" xlink:to="loc_moh_PaymentsForMedicalCareCostsAbstract_401e1f5c-cf63-4862-a551-d9d58f7b05dc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1_1cd4ad24-ab50-4b5a-8324-c1469cfd3623" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_moh_PaymentsForMedicalCareCostsAbstract_401e1f5c-cf63-4862-a551-d9d58f7b05dc" xlink:to="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1_1cd4ad24-ab50-4b5a-8324-c1469cfd3623" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1_22b60cf3-a378-42c5-8b5e-fbc89c9def06" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_moh_PaymentsForMedicalCareCostsAbstract_401e1f5c-cf63-4862-a551-d9d58f7b05dc" xlink:to="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1_22b60cf3-a378-42c5-8b5e-fbc89c9def06" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForLossesAndLossAdjustmentExpense_a97c9001-b94b-46cf-858a-79a04ceac10a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_PaymentsForLossesAndLossAdjustmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_moh_PaymentsForMedicalCareCostsAbstract_401e1f5c-cf63-4862-a551-d9d58f7b05dc" xlink:to="loc_us-gaap_PaymentsForLossesAndLossAdjustmentExpense_a97c9001-b94b-46cf-858a-79a04ceac10a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseBusinessAcquisitionsNetOfPostClosingAdjustments_aa37bf1c-6328-451e-9ba0-a8204d1ea4c2" xlink:href="moh-20240331.xsd#moh_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseBusinessAcquisitionsNetOfPostClosingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNetAbstract_46dd5c53-53f6-4112-a752-eb030d80d118" xlink:to="loc_moh_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseBusinessAcquisitionsNetOfPostClosingAdjustments_aa37bf1c-6328-451e-9ba0-a8204d1ea4c2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MedicalClaimsAndBenefitsPayableAdjustmentsChangeInProvider_575f1e09-022c-4392-921a-beab4434bd67" xlink:href="moh-20240331.xsd#moh_MedicalClaimsAndBenefitsPayableAdjustmentsChangeInProvider"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNetAbstract_46dd5c53-53f6-4112-a752-eb030d80d118" xlink:to="loc_moh_MedicalClaimsAndBenefitsPayableAdjustmentsChangeInProvider_575f1e09-022c-4392-921a-beab4434bd67" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpense_8c5eaa07-77b6-45e1-ac95-261de4e86855" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LiabilityForClaimsAndClaimsAdjustmentExpense"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/DebtScheduleofLongTermDebtDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#DebtScheduleofLongTermDebtDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/DebtScheduleofLongTermDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_9447000c-3fc8-41d0-a362-108b84ff0d4f" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_f0d26fbf-f9c7-4ade-aeeb-fb661ee59f2b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9447000c-3fc8-41d0-a362-108b84ff0d4f" xlink:to="loc_us-gaap_DebtInstrumentTable_f0d26fbf-f9c7-4ade-aeeb-fb661ee59f2b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_e329535c-75bc-4273-938c-972460499feb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f0d26fbf-f9c7-4ade-aeeb-fb661ee59f2b" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_e329535c-75bc-4273-938c-972460499feb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_e329535c-75bc-4273-938c-972460499feb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_e329535c-75bc-4273-938c-972460499feb" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_e329535c-75bc-4273-938c-972460499feb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_a7adb449-7441-4ff2-83b1-87f97e90ea1c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_e329535c-75bc-4273-938c-972460499feb" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_a7adb449-7441-4ff2-83b1-87f97e90ea1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_9f275a18-27a6-4e03-a6d3-2553b0577eef" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_a7adb449-7441-4ff2-83b1-87f97e90ea1c" xlink:to="loc_us-gaap_SeniorNotesMember_9f275a18-27a6-4e03-a6d3-2553b0577eef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_07b1e272-b77b-4478-8841-cadbe2b567dd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_f0d26fbf-f9c7-4ade-aeeb-fb661ee59f2b" xlink:to="loc_us-gaap_DebtInstrumentAxis_07b1e272-b77b-4478-8841-cadbe2b567dd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_07b1e272-b77b-4478-8841-cadbe2b567dd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_07b1e272-b77b-4478-8841-cadbe2b567dd" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_07b1e272-b77b-4478-8841-cadbe2b567dd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_d9c81215-f833-4987-b7e4-12904ee3725d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_07b1e272-b77b-4478-8841-cadbe2b567dd" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_d9c81215-f833-4987-b7e4-12904ee3725d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_A4375SeniorNotesMember_3ec65062-e61d-426e-9bd3-5f17a525c444" xlink:href="moh-20240331.xsd#moh_A4375SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_d9c81215-f833-4987-b7e4-12904ee3725d" xlink:to="loc_moh_A4375SeniorNotesMember_3ec65062-e61d-426e-9bd3-5f17a525c444" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_ThreePointEightSevenFivePercentSeniorNotesMember_e873c611-9232-4b12-856d-24e0f8d41fc4" xlink:href="moh-20240331.xsd#moh_ThreePointEightSevenFivePercentSeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_d9c81215-f833-4987-b7e4-12904ee3725d" xlink:to="loc_moh_ThreePointEightSevenFivePercentSeniorNotesMember_e873c611-9232-4b12-856d-24e0f8d41fc4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_A3875SeniorNotesMember_54f4be18-acc3-4b9c-a327-ab6dbb0742a4" xlink:href="moh-20240331.xsd#moh_A3875SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_d9c81215-f833-4987-b7e4-12904ee3725d" xlink:to="loc_moh_A3875SeniorNotesMember_54f4be18-acc3-4b9c-a327-ab6dbb0742a4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_b8b750e8-bb51-4f87-9302-fb7cff15dd17" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9447000c-3fc8-41d0-a362-108b84ff0d4f" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_b8b750e8-bb51-4f87-9302-fb7cff15dd17" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_LongTermDebtNoncurrentNetOfUnamortizedDebtDiscount_6927c7cf-7410-4c50-af36-ea5eb4e03075" xlink:href="moh-20240331.xsd#moh_LongTermDebtNoncurrentNetOfUnamortizedDebtDiscount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9447000c-3fc8-41d0-a362-108b84ff0d4f" xlink:to="loc_moh_LongTermDebtNoncurrentNetOfUnamortizedDebtDiscount_6927c7cf-7410-4c50-af36-ea5eb4e03075" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_56b954df-a6f0-4f7a-8494-1aca561a2d2c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DeferredFinanceCostsNoncurrentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9447000c-3fc8-41d0-a362-108b84ff0d4f" xlink:to="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_56b954df-a6f0-4f7a-8494-1aca561a2d2c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_813c9cd9-6124-49ab-b8ff-8bec2c8c315a" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9447000c-3fc8-41d0-a362-108b84ff0d4f" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_813c9cd9-6124-49ab-b8ff-8bec2c8c315a" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/DebtNarrativeDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#DebtNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/DebtNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_93631c10-1259-4c1f-8a4c-0299bf64d86c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_4120f9fd-59e2-4d9d-a80a-82fe57261f11" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_93631c10-1259-4c1f-8a4c-0299bf64d86c" xlink:to="loc_us-gaap_DebtInstrumentTable_4120f9fd-59e2-4d9d-a80a-82fe57261f11" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_ea9433dc-1683-4062-9850-83c229729371" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4120f9fd-59e2-4d9d-a80a-82fe57261f11" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_ea9433dc-1683-4062-9850-83c229729371" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_ea9433dc-1683-4062-9850-83c229729371_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_ea9433dc-1683-4062-9850-83c229729371" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_ea9433dc-1683-4062-9850-83c229729371_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_86ab07a3-b1dd-4f54-baee-0456de66a308" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_ea9433dc-1683-4062-9850-83c229729371" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_86ab07a3-b1dd-4f54-baee-0456de66a308" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_7bcd76bc-7c39-437d-ac31-3ff55d276be7" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_86ab07a3-b1dd-4f54-baee-0456de66a308" xlink:to="loc_us-gaap_LineOfCreditMember_7bcd76bc-7c39-437d-ac31-3ff55d276be7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_1619b0c7-9c51-4699-9214-37ef3cf9a797" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_86ab07a3-b1dd-4f54-baee-0456de66a308" xlink:to="loc_us-gaap_SeniorNotesMember_1619b0c7-9c51-4699-9214-37ef3cf9a797" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_064dad95-6ed3-4f0d-8809-75d813fb4a7b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4120f9fd-59e2-4d9d-a80a-82fe57261f11" xlink:to="loc_us-gaap_CreditFacilityAxis_064dad95-6ed3-4f0d-8809-75d813fb4a7b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_064dad95-6ed3-4f0d-8809-75d813fb4a7b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_064dad95-6ed3-4f0d-8809-75d813fb4a7b" xlink:to="loc_us-gaap_CreditFacilityDomain_064dad95-6ed3-4f0d-8809-75d813fb4a7b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_c5957cea-db63-4af9-900a-9e0b669c34eb" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_064dad95-6ed3-4f0d-8809-75d813fb4a7b" xlink:to="loc_us-gaap_CreditFacilityDomain_c5957cea-db63-4af9-900a-9e0b669c34eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_5f65d029-572d-4ec9-9a27-74b7e528072c" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_c5957cea-db63-4af9-900a-9e0b669c34eb" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_5f65d029-572d-4ec9-9a27-74b7e528072c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_5d957504-db1c-44cb-8004-6ee3752b03ef" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4120f9fd-59e2-4d9d-a80a-82fe57261f11" xlink:to="loc_us-gaap_DebtInstrumentAxis_5d957504-db1c-44cb-8004-6ee3752b03ef" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_5d957504-db1c-44cb-8004-6ee3752b03ef_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_5d957504-db1c-44cb-8004-6ee3752b03ef" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_5d957504-db1c-44cb-8004-6ee3752b03ef_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_ea317f24-9c4d-4890-9c34-86b0289b2cb9" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_5d957504-db1c-44cb-8004-6ee3752b03ef" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_ea317f24-9c4d-4890-9c34-86b0289b2cb9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_A4375SeniorNotesMember_2198b7a5-aa7f-4bc8-8f34-fde45ad2315a" xlink:href="moh-20240331.xsd#moh_A4375SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ea317f24-9c4d-4890-9c34-86b0289b2cb9" xlink:to="loc_moh_A4375SeniorNotesMember_2198b7a5-aa7f-4bc8-8f34-fde45ad2315a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_ThreePointEightSevenFivePercentSeniorNotesMember_a8f4e90b-f0aa-4a70-8a12-6656e8413b9c" xlink:href="moh-20240331.xsd#moh_ThreePointEightSevenFivePercentSeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ea317f24-9c4d-4890-9c34-86b0289b2cb9" xlink:to="loc_moh_ThreePointEightSevenFivePercentSeniorNotesMember_a8f4e90b-f0aa-4a70-8a12-6656e8413b9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_A3875SeniorNotesMember_b416c8db-4966-4a7b-9175-c666db378a22" xlink:href="moh-20240331.xsd#moh_A3875SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ea317f24-9c4d-4890-9c34-86b0289b2cb9" xlink:to="loc_moh_A3875SeniorNotesMember_b416c8db-4966-4a7b-9175-c666db378a22" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_88835b76-c0af-4fe2-bfa4-003080328356" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_93631c10-1259-4c1f-8a4c-0299bf64d86c" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_88835b76-c0af-4fe2-bfa4-003080328356" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_fc76ce6b-883b-49dc-9086-fb4264d7ba87" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_93631c10-1259-4c1f-8a4c-0299bf64d86c" xlink:to="loc_us-gaap_DebtInstrumentTerm_fc76ce6b-883b-49dc-9086-fb4264d7ba87" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_22bd8398-ad3d-42f4-9305-42b71fd8e3d8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_93631c10-1259-4c1f-8a4c-0299bf64d86c" xlink:to="loc_us-gaap_LineOfCredit_22bd8398-ad3d-42f4-9305-42b71fd8e3d8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_a651b4b3-141d-4732-91d1-0f73e42c8a10" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_93631c10-1259-4c1f-8a4c-0299bf64d86c" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_a651b4b3-141d-4732-91d1-0f73e42c8a10" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_f030ca51-82a2-45fe-a5fc-a3b8f6261713" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_93631c10-1259-4c1f-8a4c-0299bf64d86c" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_f030ca51-82a2-45fe-a5fc-a3b8f6261713" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/SegmentsOperatingSegmentInformationDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#SegmentsOperatingSegmentInformationDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/SegmentsOperatingSegmentInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_9533a96b-6c23-4881-bf96-901efc835ad5" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f52e8554-9402-49a6-ae8d-9cab470dda08" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_9533a96b-6c23-4881-bf96-901efc835ad5" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f52e8554-9402-49a6-ae8d-9cab470dda08" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_5faa18f3-c387-4b4c-9c04-8de22b65af92" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f52e8554-9402-49a6-ae8d-9cab470dda08" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_5faa18f3-c387-4b4c-9c04-8de22b65af92" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_5faa18f3-c387-4b4c-9c04-8de22b65af92_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_5faa18f3-c387-4b4c-9c04-8de22b65af92" xlink:to="loc_us-gaap_SegmentDomain_5faa18f3-c387-4b4c-9c04-8de22b65af92_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_48488455-ff30-48e6-999c-1dca3c5083fe" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_5faa18f3-c387-4b4c-9c04-8de22b65af92" xlink:to="loc_us-gaap_SegmentDomain_48488455-ff30-48e6-999c-1dca3c5083fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MedicaidMember_e73f3914-c4c4-4041-945b-5f1db09960c7" xlink:href="moh-20240331.xsd#moh_MedicaidMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_48488455-ff30-48e6-999c-1dca3c5083fe" xlink:to="loc_moh_MedicaidMember_e73f3914-c4c4-4041-945b-5f1db09960c7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MedicareMember_55ca0743-6af0-4ea9-8a55-168b697ded8a" xlink:href="moh-20240331.xsd#moh_MedicareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_48488455-ff30-48e6-999c-1dca3c5083fe" xlink:to="loc_moh_MedicareMember_55ca0743-6af0-4ea9-8a55-168b697ded8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MarketplaceMember_172ad9b3-2b20-4beb-8a6e-24ba13f5072c" xlink:href="moh-20240331.xsd#moh_MarketplaceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_48488455-ff30-48e6-999c-1dca3c5083fe" xlink:to="loc_moh_MarketplaceMember_172ad9b3-2b20-4beb-8a6e-24ba13f5072c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_OtherProgramMember_d83f089d-5af6-4c95-a52e-160a5b15474b" xlink:href="moh-20240331.xsd#moh_OtherProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_48488455-ff30-48e6-999c-1dca3c5083fe" xlink:to="loc_moh_OtherProgramMember_d83f089d-5af6-4c95-a52e-160a5b15474b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_8cd65587-6481-451a-86a6-43fda52183cf" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_9533a96b-6c23-4881-bf96-901efc835ad5" xlink:to="loc_us-gaap_Revenues_8cd65587-6481-451a-86a6-43fda52183cf" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.molinahealthcare.com/role/SegmentsReconciliationofGrossMargintoConsolidatedIncomeDetails" xlink:type="simple" xlink:href="moh-20240331.xsd#SegmentsReconciliationofGrossMargintoConsolidatedIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.molinahealthcare.com/role/SegmentsReconciliationofGrossMargintoConsolidatedIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_95379465-dfd2-447a-8235-3a455a2b36b1" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1c659568-72d7-4698-9716-34f652486389" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_95379465-dfd2-447a-8235-3a455a2b36b1" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1c659568-72d7-4698-9716-34f652486389" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_c8d6c015-8a12-4024-9f1e-402baba0e85b" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1c659568-72d7-4698-9716-34f652486389" xlink:to="loc_srt_ConsolidationItemsAxis_c8d6c015-8a12-4024-9f1e-402baba0e85b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_c8d6c015-8a12-4024-9f1e-402baba0e85b_default" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_c8d6c015-8a12-4024-9f1e-402baba0e85b" xlink:to="loc_srt_ConsolidationItemsDomain_c8d6c015-8a12-4024-9f1e-402baba0e85b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_c82fbf72-016e-42f7-b0e7-659ce3dd10e4" xlink:href="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_c8d6c015-8a12-4024-9f1e-402baba0e85b" xlink:to="loc_srt_ConsolidationItemsDomain_c82fbf72-016e-42f7-b0e7-659ce3dd10e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_1d52fc82-c44e-4f8e-ab9e-d64d04c7805b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_c82fbf72-016e-42f7-b0e7-659ce3dd10e4" xlink:to="loc_us-gaap_OperatingSegmentsMember_1d52fc82-c44e-4f8e-ab9e-d64d04c7805b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MaterialReconcilingItemsMember_984def2b-96b0-4f39-94ba-0cc0f77e5846" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_MaterialReconcilingItemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_c82fbf72-016e-42f7-b0e7-659ce3dd10e4" xlink:to="loc_us-gaap_MaterialReconcilingItemsMember_984def2b-96b0-4f39-94ba-0cc0f77e5846" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_a0e4261b-cf23-4a3e-88cf-9661ab4f2636" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1c659568-72d7-4698-9716-34f652486389" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_a0e4261b-cf23-4a3e-88cf-9661ab4f2636" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_a0e4261b-cf23-4a3e-88cf-9661ab4f2636_default" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_a0e4261b-cf23-4a3e-88cf-9661ab4f2636" xlink:to="loc_us-gaap_SegmentDomain_a0e4261b-cf23-4a3e-88cf-9661ab4f2636_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_3a9bdddb-b90b-47db-9c97-6fdd55ccf013" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_a0e4261b-cf23-4a3e-88cf-9661ab4f2636" xlink:to="loc_us-gaap_SegmentDomain_3a9bdddb-b90b-47db-9c97-6fdd55ccf013" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MedicaidMember_bf71df48-b269-4c89-bebb-7f0a97160f49" xlink:href="moh-20240331.xsd#moh_MedicaidMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3a9bdddb-b90b-47db-9c97-6fdd55ccf013" xlink:to="loc_moh_MedicaidMember_bf71df48-b269-4c89-bebb-7f0a97160f49" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MedicareMember_dbb545a1-afcf-491b-8d30-f98551f159dc" xlink:href="moh-20240331.xsd#moh_MedicareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3a9bdddb-b90b-47db-9c97-6fdd55ccf013" xlink:to="loc_moh_MedicareMember_dbb545a1-afcf-491b-8d30-f98551f159dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_MarketplaceMember_cf4e379e-f930-4696-965a-427cf08d8ab8" xlink:href="moh-20240331.xsd#moh_MarketplaceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3a9bdddb-b90b-47db-9c97-6fdd55ccf013" xlink:to="loc_moh_MarketplaceMember_cf4e379e-f930-4696-965a-427cf08d8ab8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_OtherProgramMember_76893dae-8cbb-448e-864a-f58f38e93dbc" xlink:href="moh-20240331.xsd#moh_OtherProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3a9bdddb-b90b-47db-9c97-6fdd55ccf013" xlink:to="loc_moh_OtherProgramMember_76893dae-8cbb-448e-864a-f58f38e93dbc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_fa1667d0-7a6c-4518-ad7a-9a4f29ddebd8" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_95379465-dfd2-447a-8235-3a455a2b36b1" xlink:to="loc_us-gaap_GrossProfit_fa1667d0-7a6c-4518-ad7a-9a4f29ddebd8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingIncome_f547f7c4-b6d3-47bf-ae97-5e236748b7d6" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OtherOperatingIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_95379465-dfd2-447a-8235-3a455a2b36b1" xlink:to="loc_us-gaap_OtherOperatingIncome_f547f7c4-b6d3-47bf-ae97-5e236748b7d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_1aaff291-9ff5-40de-b775-1854ec5ba60b" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_CostsAndExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_95379465-dfd2-447a-8235-3a455a2b36b1" xlink:to="loc_us-gaap_CostsAndExpenses_1aaff291-9ff5-40de-b775-1854ec5ba60b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_50d6abbc-c004-46e9-9f5e-b6b30988b650" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_95379465-dfd2-447a-8235-3a455a2b36b1" xlink:to="loc_us-gaap_OperatingIncomeLoss_50d6abbc-c004-46e9-9f5e-b6b30988b650" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_ba6ba280-a9c2-4366-a046-2d01dc823a1d" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_95379465-dfd2-447a-8235-3a455a2b36b1" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_ba6ba280-a9c2-4366-a046-2d01dc823a1d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_91b2cd47-1b48-438d-9a90-4c105e8ad3cd" xlink:href="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_95379465-dfd2-447a-8235-3a455a2b36b1" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_91b2cd47-1b48-438d-9a90-4c105e8ad3cd" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2023/ecd-2023.xsd#IndividualsOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ecd_AllIndividualsMember" xlink:href="https://xbrl.sec.gov/ecd/2023/ecd-2023.xsd#ecd_AllIndividualsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_moh_JamesWoysMember_7e6c56a8-12bc-4c96-b20e-e38cf3bae751" xlink:href="moh-20240331.xsd#moh_JamesWoysMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_moh_JamesWoysMember_7e6c56a8-12bc-4c96-b20e-e38cf3bae751" xlink:type="arc" order="2"/>
  </link:definitionLink>
</link:linkbase>
