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

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2023 Workiva-->
<!--r:d336c77f-0182-430f-aafd-65f8af48c151,g:e68a139c-fc33-46e6-ae75-8f640423e1f7-->
<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://xbrl.sec.gov/ecd/role/PvpAdjustmentsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2022q4/ecd-2022q4.xsd#PvpAdjustmentsOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/role/PvpAdjustmentsOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ecd_AllAdjToCompMember" xlink:href="https://xbrl.sec.gov/ecd/2022q4/ecd-2022q4.xsd#ecd_AllAdjToCompMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_vcyt_EquityAwardsReportedValueMember_b6480790-4a35-4af7-b6f6-5a4f9050e89f" xlink:href="vcyt-20230417.xsd#vcyt_EquityAwardsReportedValueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllAdjToCompMember" xlink:to="loc_vcyt_EquityAwardsReportedValueMember_b6480790-4a35-4af7-b6f6-5a4f9050e89f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_vcyt_EquityAwardAdjustmentsMember_25532620-d4ee-43a1-88ab-cf19ec52f7b5" xlink:href="vcyt-20230417.xsd#vcyt_EquityAwardAdjustmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllAdjToCompMember" xlink:to="loc_vcyt_EquityAwardAdjustmentsMember_25532620-d4ee-43a1-88ab-cf19ec52f7b5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_vcyt_EquityAwardsGrantedDuringTheYearUnvestedMember_e2be8633-e612-4627-956e-44d8c09908d2" xlink:href="vcyt-20230417.xsd#vcyt_EquityAwardsGrantedDuringTheYearUnvestedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllAdjToCompMember" xlink:to="loc_vcyt_EquityAwardsGrantedDuringTheYearUnvestedMember_e2be8633-e612-4627-956e-44d8c09908d2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_vcyt_EquityAwardsGrantedInPriorYearsUnvestedMember_6ad50b4c-502b-40a3-bd5e-7ff1433f5f32" xlink:href="vcyt-20230417.xsd#vcyt_EquityAwardsGrantedInPriorYearsUnvestedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllAdjToCompMember" xlink:to="loc_vcyt_EquityAwardsGrantedInPriorYearsUnvestedMember_6ad50b4c-502b-40a3-bd5e-7ff1433f5f32" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_vcyt_EquityAwardsGrantedDuringTheYearVestedMember_5ecba01e-0e0d-4cd0-b329-68371fe3f14d" xlink:href="vcyt-20230417.xsd#vcyt_EquityAwardsGrantedDuringTheYearVestedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllAdjToCompMember" xlink:to="loc_vcyt_EquityAwardsGrantedDuringTheYearVestedMember_5ecba01e-0e0d-4cd0-b329-68371fe3f14d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_vcyt_EquityAwardsGrantedInPriorYearsVestedMember_dc04af09-77cd-4e2d-ad10-b65d5c051204" xlink:href="vcyt-20230417.xsd#vcyt_EquityAwardsGrantedInPriorYearsVestedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllAdjToCompMember" xlink:to="loc_vcyt_EquityAwardsGrantedInPriorYearsVestedMember_dc04af09-77cd-4e2d-ad10-b65d5c051204" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_vcyt_EquityAwardsThatFailedToMeetVestingConditionsMember_8f26763b-ef3e-4aab-9479-5b6c2b3dba15" xlink:href="vcyt-20230417.xsd#vcyt_EquityAwardsThatFailedToMeetVestingConditionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllAdjToCompMember" xlink:to="loc_vcyt_EquityAwardsThatFailedToMeetVestingConditionsMember_8f26763b-ef3e-4aab-9479-5b6c2b3dba15" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_vcyt_EquityAwardsValueOfDividendsAndOtherEarningsPaidAdjustmentMember_a112dc32-4404-4f49-9ced-5d4acedf6be6" xlink:href="vcyt-20230417.xsd#vcyt_EquityAwardsValueOfDividendsAndOtherEarningsPaidAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllAdjToCompMember" xlink:to="loc_vcyt_EquityAwardsValueOfDividendsAndOtherEarningsPaidAdjustmentMember_a112dc32-4404-4f49-9ced-5d4acedf6be6" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2022q4/ecd-2022q4.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/2022q4/ecd-2022q4.xsd#ecd_AllIndividualsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_vcyt_StapleyMember_326cac7b-fd80-4805-a18d-055bc8a0ae61" xlink:href="vcyt-20230417.xsd#vcyt_StapleyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_vcyt_StapleyMember_326cac7b-fd80-4805-a18d-055bc8a0ae61" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_vcyt_AndersonMember_f419bf46-92a8-42de-a157-f44b0a85c3be" xlink:href="vcyt-20230417.xsd#vcyt_AndersonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_vcyt_AndersonMember_f419bf46-92a8-42de-a157-f44b0a85c3be" xlink:type="arc" order="3"/>
  </link:definitionLink>
</link:linkbase>
