<SEC-DOCUMENT>0000215457-19-006584-index.html : 20190208
<SEC-HEADER>0000215457-19-006584.hdr.sgml : 20190208
<ACCEPTANCE-DATETIME>20190207180858
ACCESSION NUMBER:		0000215457-19-006584
CONFORMED SUBMISSION TYPE:	SC 13G
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20190208
DATE AS OF CHANGE:		20190207

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
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-54369
		FILM NUMBER:		19576385

	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:			BlackRock Inc.
		CENTRAL INDEX KEY:			0001364742
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
		IRS NUMBER:				320174431
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G

	BUSINESS ADDRESS:	
		STREET 1:		55 EAST 52ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10055
		BUSINESS PHONE:		212-810-5300

	MAIL ADDRESS:	
		STREET 1:		55 EAST 52ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10055

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BlackRock, Inc.
		DATE OF NAME CHANGE:	20060929

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	New BlackRock, Inc.
		DATE OF NAME CHANGE:	20060601
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G
<SEQUENCE>1
<FILENAME>us22160n1090_020719.txt
<TEXT>
Document 1 - file: us22160n1090_020719.txt

</DOCUMENT>
</SEC-DOCUMENT>