<SEC-DOCUMENT>0001104659-17-021670-index.html : 20170405
<SEC-HEADER>0001104659-17-021670.hdr.sgml : 20170405
<ACCEPTANCE-DATETIME>20170405161054
ACCESSION NUMBER:		0001104659-17-021670
CONFORMED SUBMISSION TYPE:	DEFA14A
PUBLIC DOCUMENT COUNT:		5
FILED AS OF DATE:		20170405
DATE AS OF CHANGE:		20170405
EFFECTIVENESS DATE:		20170405

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CoreSite Realty Corp
		CENTRAL INDEX KEY:			0001490892
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		DEFA14A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34877
		FILM NUMBER:		17742674

	BUSINESS ADDRESS:	
		STREET 1:		1001 17TH STREET
		STREET 2:		SUITE 500
		CITY:			DENVER
		STATE:			CO
		ZIP:			80202
		BUSINESS PHONE:		(866) 777-2673

	MAIL ADDRESS:	
		STREET 1:		1001 17TH STREET
		STREET 2:		SUITE 500
		CITY:			DENVER
		STATE:			CO
		ZIP:			80202
</SEC-HEADER>
<DOCUMENT>
<TYPE>DEFA14A
<SEQUENCE>1
<FILENAME>a17-2221_5defa14a.htm
<DESCRIPTION>DEFA14A
<TEXT>
Document 1 - file: a17-2221_5defa14a.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>2
<FILENAME>g22215bgi001.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 2 - file: g22215bgi001.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>g22215bgi002.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: g22215bgi002.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>g22215bgi003.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 4 - file: g22215bgi003.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>5
<FILENAME>g22215bgi004.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 5 - file: g22215bgi004.gif

</DOCUMENT>
</SEC-DOCUMENT>