<SEC-DOCUMENT>0001057352-17-000041-index.html : 20170627
<SEC-HEADER>0001057352-17-000041.hdr.sgml : 20170627
<ACCEPTANCE-DATETIME>20170627163336
ACCESSION NUMBER:		0001057352-17-000041
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170626
FILED AS OF DATE:		20170627
DATE AS OF CHANGE:		20170627

ISSUER:		

	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

	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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KLEIN MICHAEL R
		CENTRAL INDEX KEY:			0001066062

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-24531
		FILM NUMBER:		17932739

	MAIL ADDRESS:	
		STREET 1:		2001 K STREET, N.W.
		STREET 2:		SUITE 206
		CITY:			WASHINGTON
		STATE:			DC
		ZIP:			20006
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_149859560295003.xml
<DESCRIPTION>FORM 4
<TEXT>
Document 1 - file: wf-form4_149859560295003.html

Document 1 - RAW XML: wf-form4_149859560295003.xml

</DOCUMENT>
</SEC-DOCUMENT>