<SEC-DOCUMENT>0001193125-21-349661-index.html : 20211207
<SEC-HEADER>0001193125-21-349661.hdr.sgml : 20211207
<ACCEPTANCE-DATETIME>20211207080104
ACCESSION NUMBER:		0001193125-21-349661
CONFORMED SUBMISSION TYPE:	SC TO-T/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20211207
DATE AS OF CHANGE:		20211207

SUBJECT COMPANY:	

	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:		SC TO-T/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-85695
		FILM NUMBER:		211474694

	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

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AMERICAN TOWER CORP /MA/
		CENTRAL INDEX KEY:			0001053507
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				650723837
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC TO-T/A

	BUSINESS ADDRESS:	
		STREET 1:		116 HUNTINGTON AVE
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		6173757500

	MAIL ADDRESS:	
		STREET 1:		116 HUNTINGTON AVE
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	AMERICAN TOWER SYSTEMS CORP
		DATE OF NAME CHANGE:	19980128
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC TO-T/A
<SEQUENCE>1
<FILENAME>d185249dsctota.htm
<DESCRIPTION>SC TO-T/A
<TEXT>
Document 1 - file: d185249dsctota.htm

</DOCUMENT>
</SEC-DOCUMENT>