<SEC-DOCUMENT>0000812295-17-000054-index.html : 20170213
<SEC-HEADER>0000812295-17-000054.hdr.sgml : 20170213
<ACCEPTANCE-DATETIME>20170213143828
ACCESSION NUMBER:		0000812295-17-000054
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20170213
DATE AS OF CHANGE:		20170213

SUBJECT COMPANY:	

	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:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-54369
		FILM NUMBER:		17598264

	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

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			JANUS CAPITAL MANAGEMENT LLC
		CENTRAL INDEX KEY:			0000812295
		STANDARD INDUSTRIAL CLASSIFICATION:	UNKNOWN SIC - 0000 [0000]
		IRS NUMBER:				753019302
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		151 DETROIT ST.
		CITY:			DENVER
		STATE:			CO
		ZIP:			80206-4805
		BUSINESS PHONE:		3033333863

	MAIL ADDRESS:	
		STREET 1:		151 DETROIT ST.
		CITY:			DENVER
		STATE:			CO
		ZIP:			80206-4805

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	JANUS CAPITAL GROUP INC
		DATE OF NAME CHANGE:	20030103

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	JANUS CAPITAL MANAGEMENT LLC
		DATE OF NAME CHANGE:	20020424

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	JANUS CAPITAL CORP
		DATE OF NAME CHANGE:	19931213
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>csgp2102017.txt
<DESCRIPTION>SC 13G/A CSGP 12.31.16
<TEXT>
Document 1 - file: csgp2102017.txt

</DOCUMENT>
</SEC-DOCUMENT>