<SEC-DOCUMENT>0001193125-18-143218-index.html : 20180430
<SEC-HEADER>0001193125-18-143218.hdr.sgml : 20180430
<ACCEPTANCE-DATETIME>20180430162104
ACCESSION NUMBER:		0001193125-18-143218
CONFORMED SUBMISSION TYPE:	497K
PUBLIC DOCUMENT COUNT:		7
FILED AS OF DATE:		20180430
DATE AS OF CHANGE:		20180430
EFFECTIVENESS DATE:		20180430

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:		18790081

	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>S000009186
<SERIES-NAME>Columbia Acorn USA
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024962
<CLASS-CONTRACT-NAME>Columbia Acorn USA Class A
<CLASS-CONTRACT-TICKER-SYMBOL>LAUAX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024964
<CLASS-CONTRACT-NAME>Columbia Acorn USA Class C
<CLASS-CONTRACT-TICKER-SYMBOL>LAUCX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024965
<CLASS-CONTRACT-NAME>Columbia Acorn USA Institutional Class
<CLASS-CONTRACT-TICKER-SYMBOL>AUSAX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122740
<CLASS-CONTRACT-NAME>Columbia Acorn USA Advisor Class
<CLASS-CONTRACT-TICKER-SYMBOL>CUSAX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122741
<CLASS-CONTRACT-NAME>Columbia Acorn USA Institutional 2 Class
<CLASS-CONTRACT-TICKER-SYMBOL>CYSRX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122742
<CLASS-CONTRACT-NAME>Columbia Acorn USA Institutional 3 Class
<CLASS-CONTRACT-TICKER-SYMBOL>CUSYX
</CLASS-CONTRACT>
</SERIES>
</EXISTING-SERIES-AND-CLASSES-CONTRACTS>
</SERIES-AND-CLASSES-CONTRACTS-DATA>
</SEC-HEADER>
<DOCUMENT>
<TYPE>497K
<SEQUENCE>1
<FILENAME>d562138d497k.htm
<DESCRIPTION>COLUMBIA ACORN TRUST
<TEXT>
Document 1 - file: d562138d497k.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>2
<FILENAME>g607013acorn_cticyanc.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 2 - file: g607013acorn_cticyanc.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>g607013acorns_sized.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: g607013acorns_sized.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>g607013bg_604.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 4 - file: g607013bg_604.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>5
<FILENAME>g607013coltnlogospot.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 5 - file: g607013coltnlogospot.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>6
<FILENAME>g607013cyanblocks.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 6 - file: g607013cyanblocks.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>7
<FILENAME>g607013img02f060a51.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 7 - file: g607013img02f060a51.gif

</DOCUMENT>
</SEC-DOCUMENT>