    <SEC-DOCUMENT>0001193125-26-197274-index.html : 20260430
    <SEC-HEADER>0001193125-26-197274.hdr.sgml : 20260430
    <ACCEPTANCE-DATETIME>20260430160947
    ACCESSION NUMBER:		0001193125-26-197274
    CONFORMED SUBMISSION TYPE:	ARS
    PUBLIC DOCUMENT COUNT:		1
    CONFORMED PERIOD OF REPORT:	20251231
    FILED AS OF DATE:		20260430
    DATE AS OF CHANGE:		20260430
    EFFECTIVENESS DATE:		20260430

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			COSTAR GROUP, INC.
    		CENTRAL INDEX KEY:			0001057352
    		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-BUSINESS SERVICES, NEC [7389]
    		ORGANIZATION NAME:           	07 Trade & Services
    		EIN:				522091509
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		ARS
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	000-24531
    		FILM NUMBER:		26925338

    	BUSINESS ADDRESS:
    		STREET 1:		1201 WILSON BLVD.
    		CITY:			ARLINGTON
    		STATE:			VA
    		ZIP:			22209
    		BUSINESS PHONE:		2023466500

    	MAIL ADDRESS:
    		STREET 1:		1201 WILSON BLVD.
    		CITY:			ARLINGTON
    		STATE:			VA
    		ZIP:			22209

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	COSTAR GROUP INC
    		DATE OF NAME CHANGE:	19990805
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>ARS
    <SEQUENCE>1
    <FILENAME>d903162dars.pdf
    <DESCRIPTION>ARS
    <TEXT>
    Document 1 - file: d903162dars.pdf

    </DOCUMENT>
    </SEC-DOCUMENT>