<SEC-DOCUMENT>0001057352-21-000059-index.html : 20210419
<SEC-HEADER>0001057352-21-000059.hdr.sgml : 20210419
<ACCEPTANCE-DATETIME>20210419161458
ACCESSION NUMBER:		0001057352-21-000059
CONFORMED SUBMISSION TYPE:	DEF 14A
PUBLIC DOCUMENT COUNT:		14
CONFORMED PERIOD OF REPORT:	20210602
FILED AS OF DATE:		20210419
DATE AS OF CHANGE:		20210419

FILER:

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

	FILING VALUES:
		FORM TYPE:		DEF 14A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-24531
		FILM NUMBER:		21834771

	BUSINESS ADDRESS:	
		STREET 1:		1331 L STREET, NW
		CITY:			WASHINGTON
		STATE:			DC
		ZIP:			20005
		BUSINESS PHONE:		2023466500

	MAIL ADDRESS:	
		STREET 1:		1331 L STREET, NW
		CITY:			WASHINGTON
		STATE:			DC
		ZIP:			20005

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	COSTAR GROUP INC
		DATE OF NAME CHANGE:	19990805
</SEC-HEADER>
<DOCUMENT>
<TYPE>DEF 14A
<SEQUENCE>1
<FILENAME>a2021proxystatement-def14a.htm
<DESCRIPTION>DEF 14A
<TEXT>
Document 1 - file: a2021proxystatement-def14a.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>2
<FILENAME>a20200310124736a031.jpg
<TEXT>
Document 2 - file: a20200310124736a031.jpg

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<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>a3a041.jpg
<TEXT>
Document 3 - file: a3a041.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>acsignaturea041.jpg
<TEXT>
Document 4 - file: acsignaturea041.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>5
<FILENAME>boardcomposition1.jpg
<TEXT>
Document 5 - file: boardcomposition1.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>6
<FILENAME>card11.jpg
<TEXT>
Document 6 - file: card11.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>7
<FILENAME>card21.jpg
<TEXT>
Document 7 - file: card21.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>8
<FILENAME>ebitda1.jpg
<TEXT>
Document 8 - file: ebitda1.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>9
<FILENAME>horizonchart-20211.jpg
<TEXT>
Document 9 - file: horizonchart-20211.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>10
<FILENAME>netincome1.jpg
<TEXT>
Document 10 - file: netincome1.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>11
<FILENAME>operating1.jpg
<TEXT>
Document 11 - file: operating1.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>12
<FILENAME>pie11.jpg
<TEXT>
Document 12 - file: pie11.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>13
<FILENAME>pie21.jpg
<TEXT>
Document 13 - file: pie21.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>14
<FILENAME>variablepaycharta031.jpg
<TEXT>
Document 14 - file: variablepaycharta031.jpg

</DOCUMENT>
</SEC-DOCUMENT>