<SEC-DOCUMENT>0001422849-25-000100.txt : 20251113
<SEC-HEADER>0001422849-25-000100.hdr.sgml : 20251113
<ACCEPTANCE-DATETIME>20251113190613
ACCESSION NUMBER:		0001422849-25-000100
CONFORMED SUBMISSION TYPE:	SCHEDULE 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20251113
DATE AS OF CHANGE:		20251113

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COMFORT SYSTEMS USA INC
		CENTRAL INDEX KEY:			0001035983
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRICAL WORK [1731]
		ORGANIZATION NAME:           	05 Real Estate & Construction
		EIN:				760526487
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-53565
		FILM NUMBER:		251480385

	BUSINESS ADDRESS:	
		STREET 1:		9753 KATY FREEWAY
		STREET 2:		SUITE 700
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77024
		BUSINESS PHONE:		7138309600

	MAIL ADDRESS:	
		STREET 1:		9753 KATY FREEWAY
		STREET 2:		SUITE 700
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77024

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Capital World Investors
		CENTRAL INDEX KEY:			0001422849
		ORGANIZATION NAME:           	
		EIN:				951411037
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		333 SOUTH HOPE STREET
		STREET 2:		55TH FLOOR
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90071
		BUSINESS PHONE:		213-486-9200

	MAIL ADDRESS:	
		STREET 1:		333 SOUTH HOPE STREET
		STREET 2:		55TH FLOOR
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90071
</SEC-HEADER>
<DOCUMENT>
<TYPE>SCHEDULE 13G/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
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  <headerData>
    <submissionType>SCHEDULE 13G/A</submissionType>
    <previousAccessionNumber>0001422849-24-000091</previousAccessionNumber>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001422849</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <coverPageHeader>
      <amendmentNo>1</amendmentNo>
      <securitiesClassTitle>Common Stock</securitiesClassTitle>
      <eventDateRequiresFilingThisStatement>09/30/2025</eventDateRequiresFilingThisStatement>
      <issuerInfo>
        <issuerCik>0001035983</issuerCik>
        <issuerName>Comfort Systems USA, Inc.</issuerName>
        <issuerCusip>199908104</issuerCusip>
        <issuerPrincipalExecutiveOfficeAddress>
          <com:street1>9753 KATY FREEWAY</com:street1>
          <com:street2>SUITE 700</com:street2>
          <com:city>HOUSTON</com:city>
          <com:stateOrCountry>X1</com:stateOrCountry>
          <com:zipCode>77024</com:zipCode>
        </issuerPrincipalExecutiveOfficeAddress>
      </issuerInfo>
      <designateRulesPursuantThisScheduleFiled>
        <designateRulePursuantThisScheduleFiled>Rule 13d-1(b)</designateRulePursuantThisScheduleFiled>
      </designateRulesPursuantThisScheduleFiled>
    </coverPageHeader>
    <coverPageHeaderReportingPersonDetails>

      <reportingPersonName>Capital World Investors</reportingPersonName>
      <citizenshipOrOrganization>DE</citizenshipOrOrganization>
      <reportingPersonBeneficiallyOwnedNumberOfShares>
        <soleVotingPower>1799310</soleVotingPower>
        <sharedVotingPower>0</sharedVotingPower>
        <soleDispositivePower>1799310</soleDispositivePower>
        <sharedDispositivePower>0</sharedDispositivePower>
      </reportingPersonBeneficiallyOwnedNumberOfShares>
      <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>1799310.00</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
      <classPercent>5.1</classPercent>
      <typeOfReportingPerson>IA</typeOfReportingPerson>
    </coverPageHeaderReportingPersonDetails>
    <items>
      <item1>
        <issuerName>Comfort Systems USA, Inc.</issuerName>
        <issuerPrincipalExecutiveOfficeAddress>9753 KATY FREEWAY, SUITE 700, HOUSTON, TX 77024</issuerPrincipalExecutiveOfficeAddress>
      </item1>
      <item2>
        <filingPersonName>Capital World Investors</filingPersonName>
        <principalBusinessOfficeOrResidenceAddress>333 SOUTH HOPE STREET, 55TH FLOOR, LOS ANGELES, CALIFORNIA  90071
</principalBusinessOfficeOrResidenceAddress>
        <citizenship>N/A</citizenship>
      </item2>
      <item3>
        <notApplicableFlag>N</notApplicableFlag>
        <typeOfPersonFiling>IA</typeOfPersonFiling>
      </item3>
      <item4>
        <amountBeneficiallyOwned>1,799,310 **

**Capital World Investors ("CWI") is a division of Capital Research and Management Company ("CRMC"), as well as its investment management subsidiaries and affiliates Capital Bank and Trust Company, Capital International, Inc., Capital International Limited, Capital International Sarl, Capital International K.K., Capital Group Private Client Services, Inc., and Capital Group Investment Management Private Limited (together with CRMC, the "investment management entities"). CWI's divisions of each of the investment management entities collectively provide investment management services under the name "Capital World Investors." CWI is deemed to be the beneficial owner of 1,799,310 shares or 5.1% of the 35,281,452 shares believed to be outstanding.</amountBeneficiallyOwned>
        <classPercent>5.1</classPercent>
        <numberOfSharesPersonHas>
          <solePowerOrDirectToVote>1,799,310</solePowerOrDirectToVote>
          <sharedPowerOrDirectToVote>0</sharedPowerOrDirectToVote>
          <solePowerOrDirectToDispose>1,799,310</solePowerOrDirectToDispose>
          <sharedPowerOrDirectToDispose>0</sharedPowerOrDirectToDispose>
        </numberOfSharesPersonHas>
      </item4>
      <item5>
        <notApplicableFlag>Y</notApplicableFlag>
      </item5>
      <item6>
        <notApplicableFlag>Y</notApplicableFlag>
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      <item7>
        <notApplicableFlag>Y</notApplicableFlag>
      </item7>
      <item8>
        <notApplicableFlag>Y</notApplicableFlag>
      </item8>
      <item9>
        <notApplicableFlag>Y</notApplicableFlag>
      </item9>
      <item10>
        <notApplicableFlag>N</notApplicableFlag>
        <certifications>By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.</certifications>
      </item10>
    </items>
    <signatureInformation>
      <reportingPersonName>Capital World Investors</reportingPersonName>
      <signatureDetails>
        <signature>Timothy J. Moon</signature>
        <title>Vice President and Senior Counsel, Capital Research and Management Company</title>
        <date>11/13/2025</date>
      </signatureDetails>
    </signatureInformation>
  </formData>
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</DOCUMENT>
</SEC-DOCUMENT>
