<SEC-DOCUMENT>0002007317-25-000953.txt : 20250822
<SEC-HEADER>0002007317-25-000953.hdr.sgml : 20250822
<ACCEPTANCE-DATETIME>20250822162537
ACCESSION NUMBER:		0002007317-25-000953
CONFORMED SUBMISSION TYPE:	144
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20250822
DATE AS OF CHANGE:		20250822

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:		144
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	001-13011
		FILM NUMBER:		251246601

	BUSINESS ADDRESS:	
		STREET 1:		675 BERING DRIVE
		STREET 2:		SUITE 400
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77057
		BUSINESS PHONE:		7138309600

	MAIL ADDRESS:	
		STREET 1:		675 BERING DRIVE
		STREET 2:		SUITE 400
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77057

REPORTING-OWNER:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Mercado, Pablo G.
		CENTRAL INDEX KEY:			0001535246
		ORGANIZATION NAME:           	
		EIN:				000000000

	FILING VALUES:
		FORM TYPE:		144

	MAIL ADDRESS:	
		STREET 1:		920 MEMORIAL CITY WAY, SUITE 800
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77024
</SEC-HEADER>
<DOCUMENT>
<TYPE>144
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
  <headerData>
    <submissionType>144</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001535246</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0001035983</issuerCik>
      <issuerName>COMFORT SYSTEMS USA INC</issuerName>
      <secFileNumber>001-13011</secFileNumber>
      <issuerAddress>
        <com:street1>675 BERING DRIVE</com:street1>
        <com:street2>SUITE 400</com:street2>
        <com:city>HOUSTON</com:city>
        <com:stateOrCountry>TX</com:stateOrCountry>
        <com:zipCode>77057</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>7138309600</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Mercado, Pablo G.</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Officer</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>COMMON</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>MERRILL LYNCH, PIERCE, FENNER &amp; SMITH INC</name>
        <address>
          <com:street1>5910 N CENTRAL EXPRESSWAY</com:street1>
          <com:street2>SUITE 2000</com:street2>
          <com:city>DALLAS</com:city>
          <com:stateOrCountry>TX</com:stateOrCountry>
          <com:zipCode>75206</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>1078</noOfUnitsSold>
      <aggregateMarketValue>752907.54</aggregateMarketValue>
      <noOfUnitsOutstanding>35281452</noOfUnitsOutstanding>
      <approxSaleDate>08/22/2025</approxSaleDate>
      <securitiesExchangeName>NYSE</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>COMMON</securitiesClassTitle>
      <acquiredDate>09/11/2018</acquiredDate>
      <natureOfAcquisitionTransaction>PURCHASE </natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>PABLO G MERCADO</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>2615</amountOfSecuritiesAcquired>
      <paymentDate>09/11/2018</paymentDate>
      <natureOfPayment>BOUGHT IN IRA</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>08/22/2025</noticeDate>
      <signature>Pablo G. Mercado</signature>
    </noticeSignature>
  </formData>

</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
