<SEC-DOCUMENT>0001683863-24-001070-index.html : 20240301
<SEC-HEADER>0001683863-24-001070.hdr.sgml : 20240301
<ACCEPTANCE-DATETIME>20240301103855
ACCESSION NUMBER:		0001683863-24-001070
CONFORMED SUBMISSION TYPE:	N-CSR
PUBLIC DOCUMENT COUNT:		23
CONFORMED PERIOD OF REPORT:	20231231
FILED AS OF DATE:		20240301
DATE AS OF CHANGE:		20240301
EFFECTIVENESS DATE:		20240301

FILER:

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

	FILING VALUES:
		FORM TYPE:		N-CSR
		SEC ACT:		1940 Act
		SEC FILE NUMBER:	811-01829
		FILM NUMBER:		24707834

	BUSINESS ADDRESS:	
		STREET 1:		71 S. WACKER DRIVE, SUITE 2500
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606
		BUSINESS PHONE:		3126349200

	MAIL ADDRESS:	
		STREET 1:		71 S. WACKER DRIVE, SUITE 2500
		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>S000009184
<SERIES-NAME>Columbia Acorn Fund
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024954
<CLASS-CONTRACT-NAME>Columbia Acorn Fund Class A
<CLASS-CONTRACT-TICKER-SYMBOL>LACAX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024956
<CLASS-CONTRACT-NAME>Columbia Acorn Fund Class C
<CLASS-CONTRACT-TICKER-SYMBOL>LIACX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024957
<CLASS-CONTRACT-NAME>Columbia Acorn Fund Institutional Class
<CLASS-CONTRACT-TICKER-SYMBOL>ACRNX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122735
<CLASS-CONTRACT-NAME>Columbia Acorn Fund Advisor Class
<CLASS-CONTRACT-TICKER-SYMBOL>CEARX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122736
<CLASS-CONTRACT-NAME>Columbia Acorn Fund Institutional 2 Class
<CLASS-CONTRACT-TICKER-SYMBOL>CRBRX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122737
<CLASS-CONTRACT-NAME>Columbia Acorn Fund Institutional 3 Class
<CLASS-CONTRACT-TICKER-SYMBOL>CRBYX
</CLASS-CONTRACT>
</SERIES>
<SERIES>
<OWNER-CIK>0000002110
<SERIES-ID>S000009185
<SERIES-NAME>Columbia Acorn International
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024958
<CLASS-CONTRACT-NAME>Columbia Acorn International Class A
<CLASS-CONTRACT-TICKER-SYMBOL>LAIAX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024960
<CLASS-CONTRACT-NAME>Columbia Acorn International Class C
<CLASS-CONTRACT-TICKER-SYMBOL>LAICX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024961
<CLASS-CONTRACT-NAME>Columbia Acorn International Institutional Class
<CLASS-CONTRACT-TICKER-SYMBOL>ACINX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000097732
<CLASS-CONTRACT-NAME>Columbia Acorn International Class R
<CLASS-CONTRACT-TICKER-SYMBOL>CACRX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000097733
<CLASS-CONTRACT-NAME>Columbia Acorn International Institutional 2 Class
<CLASS-CONTRACT-TICKER-SYMBOL>CAIRX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122738
<CLASS-CONTRACT-NAME>Columbia Acorn International Advisor Class
<CLASS-CONTRACT-TICKER-SYMBOL>CCIRX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122739
<CLASS-CONTRACT-NAME>Columbia Acorn International Institutional 3 Class
<CLASS-CONTRACT-TICKER-SYMBOL>CCYIX
</CLASS-CONTRACT>
</SERIES>
<SERIES>
<OWNER-CIK>0000002110
<SERIES-ID>S000009188
<SERIES-NAME>Columbia Acorn International Select
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024970
<CLASS-CONTRACT-NAME>Columbia Acorn International Select Class A
<CLASS-CONTRACT-TICKER-SYMBOL>LAFAX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024972
<CLASS-CONTRACT-NAME>Columbia Acorn International Select Class C
<CLASS-CONTRACT-TICKER-SYMBOL>LFFCX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000024973
<CLASS-CONTRACT-NAME>Columbia Acorn International Select Institutional Class
<CLASS-CONTRACT-TICKER-SYMBOL>ACFFX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122746
<CLASS-CONTRACT-NAME>Columbia Acorn International Select Institutional 2 Class
<CLASS-CONTRACT-TICKER-SYMBOL>CRIRX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122747
<CLASS-CONTRACT-NAME>Columbia Acorn International Select Institutional 3 Class
<CLASS-CONTRACT-TICKER-SYMBOL>CSIRX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122748
<CLASS-CONTRACT-NAME>Columbia Acorn International Select Advisor Class
<CLASS-CONTRACT-TICKER-SYMBOL>CILRX
</CLASS-CONTRACT>
</SERIES>
<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 Institutional Class
<CLASS-CONTRACT-TICKER-SYMBOL>COTZX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122749
<CLASS-CONTRACT-NAME>Columbia Thermostat Fund Advisor Class
<CLASS-CONTRACT-TICKER-SYMBOL>CTORX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122750
<CLASS-CONTRACT-NAME>Columbia Thermostat Fund Institutional 2 Class
<CLASS-CONTRACT-TICKER-SYMBOL>CQTRX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122751
<CLASS-CONTRACT-NAME>Columbia Thermostat Fund Institutional 3 Class
<CLASS-CONTRACT-TICKER-SYMBOL>CYYYX
</CLASS-CONTRACT>
</SERIES>
<SERIES>
<OWNER-CIK>0000002110
<SERIES-ID>S000033621
<SERIES-NAME>Columbia Acorn European Fund
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000103324
<CLASS-CONTRACT-NAME>Columbia Acorn European Fund Class A
<CLASS-CONTRACT-TICKER-SYMBOL>CAEAX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000103325
<CLASS-CONTRACT-NAME>Columbia Acorn European Fund Class C
<CLASS-CONTRACT-TICKER-SYMBOL>CAECX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000103327
<CLASS-CONTRACT-NAME>Columbia Acorn European Fund Institutional Class
<CLASS-CONTRACT-TICKER-SYMBOL>CAEZX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000122752
<CLASS-CONTRACT-NAME>Columbia Acorn European Fund Institutional 2 Class
<CLASS-CONTRACT-TICKER-SYMBOL>CAEEX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000144049
<CLASS-CONTRACT-NAME>Columbia Acorn European Fund Advisor Class
<CLASS-CONTRACT-TICKER-SYMBOL>CLOFX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000171393
<CLASS-CONTRACT-NAME>Columbia Acorn European Fund Institutional 3 Class
<CLASS-CONTRACT-TICKER-SYMBOL>CAEYX
</CLASS-CONTRACT>
</SERIES>
</EXISTING-SERIES-AND-CLASSES-CONTRACTS>
</SERIES-AND-CLASSES-CONTRACTS-DATA>
</SEC-HEADER>
<DOCUMENT>
<TYPE>N-CSR
<SEQUENCE>1
<FILENAME>f37727d1.htm
<DESCRIPTION>COLUMBIA ACORN TRUST
<TEXT>
Document 1 - file: f37727d1.htm
</DOCUMENT> <DOCUMENT> <TYPE>EX-99.CODE ETH <SEQUENCE>2 <FILENAME>f37727d2.htm <DESCRIPTION>CODE OF ETHICS <TEXT> Document 2 - file: f37727d2.htm
</DOCUMENT> <DOCUMENT> <TYPE>EX-99.CERT <SEQUENCE>3 <FILENAME>f37727d3.htm <DESCRIPTION>SECTION 302 CERTIFICATION <TEXT> Document 3 - file: f37727d3.htm
</DOCUMENT> <DOCUMENT> <TYPE>EX-99.906 CERT <SEQUENCE>4 <FILENAME>f37727d4.htm <DESCRIPTION>SECTION 906 CERTIFICATION <TEXT> Document 4 - file: f37727d4.htm
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>5 <FILENAME>img1a133ecd6.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 5 - file: img1a133ecd6.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>6 <FILENAME>img39aa90e15.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 6 - file: img39aa90e15.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>7 <FILENAME>img7b7aac421.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 7 - file: img7b7aac421.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>8 <FILENAME>img9a0e9e122.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 8 - file: img9a0e9e122.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>9 <FILENAME>imga3e4e89b7.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 9 - file: imga3e4e89b7.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>10 <FILENAME>imgb053c5eb3.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 10 - file: imgb053c5eb3.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>11 <FILENAME>imgb102c91e4.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 11 - file: imgb102c91e4.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>12 <FILENAME>imgc2881f5610.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 12 - file: imgc2881f5610.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>13 <FILENAME>imgc5f5325811.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 13 - file: imgc5f5325811.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>14 <FILENAME>imgdf041d099.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 14 - file: imgdf041d099.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>15 <FILENAME>imgfef629b28.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 15 - file: imgfef629b28.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>16 <FILENAME>g1fykdhdavrl7y7h2twak.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 16 - file: g1fykdhdavrl7y7h2twak.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>17 <FILENAME>g9ghx9vrx3mwd7a6jz1up.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 17 - file: g9ghx9vrx3mwd7a6jz1up.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>18 <FILENAME>ga75chk350s37ic8xu6ei.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 18 - file: ga75chk350s37ic8xu6ei.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>19 <FILENAME>gg4nmgp0sbhdqhhrhw32q.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 19 - file: gg4nmgp0sbhdqhhrhw32q.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>20 <FILENAME>gjaujfcq0lr0r4nomjdko.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 20 - file: gjaujfcq0lr0r4nomjdko.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>21 <FILENAME>gltxzunjuh4nhivnuiwkr.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 21 - file: gltxzunjuh4nhivnuiwkr.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>22 <FILENAME>go1gjayzm25zywkb3od2v.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 22 - file: go1gjayzm25zywkb3od2v.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>23 <FILENAME>gutla2rfjbe8hyje5kiwr.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 23 - file: gutla2rfjbe8hyje5kiwr.jpg
</DOCUMENT> </SEC-DOCUMENT>