<SEC-DOCUMENT>0001193125-17-147039-index.html : 20170428
<SEC-HEADER>0001193125-17-147039.hdr.sgml : 20170428
<ACCEPTANCE-DATETIME>20170428133403
ACCESSION NUMBER:		0001193125-17-147039
CONFORMED SUBMISSION TYPE:	497K
PUBLIC DOCUMENT COUNT:		7
FILED AS OF DATE:		20170428
DATE AS OF CHANGE:		20170428
EFFECTIVENESS DATE:		20170428

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COLUMBIA ACORN TRUST
		CENTRAL INDEX KEY:			0000002110
		IRS NUMBER:				362692100
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		497K
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	002-34223
		FILM NUMBER:		17793772

	BUSINESS ADDRESS:	
		STREET 1:		227 W MONROE STE 3000
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606
		BUSINESS PHONE:		3126349200

	MAIL ADDRESS:	
		STREET 1:		227 W MONROE STE 3000
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	LIBERTY ACORN TRUST
		DATE OF NAME CHANGE:	20010424

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ACORN INVESTMENT TRUST
		DATE OF NAME CHANGE:	19940204

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ACORN FUND INC
		DATE OF NAME CHANGE:	19920703
<SERIES-AND-CLASSES-CONTRACTS-DATA>
<EXISTING-SERIES-AND-CLASSES-CONTRACTS>
<SERIES>
<OWNER-CIK>0000002110
<SERIES-ID>S000009189
<SERIES-NAME>Columbia Thermostat Fund
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024974
<CLASS-CONTRACT-NAME>Columbia Thermostat Fund Class A
<CLASS-CONTRACT-TICKER-SYMBOL>CTFAX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024976
<CLASS-CONTRACT-NAME>Columbia Thermostat Fund Class C
<CLASS-CONTRACT-TICKER-SYMBOL>CTFDX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024977
<CLASS-CONTRACT-NAME>Columbia Thermostat Fund Class Z
<CLASS-CONTRACT-TICKER-SYMBOL>COTZX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122749
<CLASS-CONTRACT-NAME>Columbia Thermostat Fund Class R4
<CLASS-CONTRACT-TICKER-SYMBOL>CTORX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122750
<CLASS-CONTRACT-NAME>Columbia Thermostat Fund Class R5
<CLASS-CONTRACT-TICKER-SYMBOL>CQTRX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122751
<CLASS-CONTRACT-NAME>Columbia Thermostat Fund Class Y
<CLASS-CONTRACT-TICKER-SYMBOL>CYYYX
</CLASS-CONTRACT>
</SERIES>
</EXISTING-SERIES-AND-CLASSES-CONTRACTS>
</SERIES-AND-CLASSES-CONTRACTS-DATA>
</SEC-HEADER>
<DOCUMENT>
<TYPE>497K
<SEQUENCE>1
<FILENAME>d361892d497k.htm
<DESCRIPTION>COLUMBIA ACORN TRUST
<TEXT>
Document 1 - file: d361892d497k.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>2
<FILENAME>g607054acorn_cticyanc.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 2 - file: g607054acorn_cticyanc.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>g607054acorns_sized.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: g607054acorns_sized.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>g607054bg_655.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 4 - file: g607054bg_655.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>5
<FILENAME>g607054coltnlogospot.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 5 - file: g607054coltnlogospot.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>6
<FILENAME>g607054cyanblocks.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 6 - file: g607054cyanblocks.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>7
<FILENAME>g607054imgbba78ae21.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 7 - file: g607054imgbba78ae21.gif

</DOCUMENT>
</SEC-DOCUMENT>