<SEC-DOCUMENT>0001683863-22-001389-index.html : 20220303
<SEC-HEADER>0001683863-22-001389.hdr.sgml : 20220303
<ACCEPTANCE-DATETIME>20220303100415
ACCESSION NUMBER:		0001683863-22-001389
CONFORMED SUBMISSION TYPE:	N-CSR
PUBLIC DOCUMENT COUNT:		24
CONFORMED PERIOD OF REPORT:	20211231
FILED AS OF DATE:		20220303
DATE AS OF CHANGE:		20220303
EFFECTIVENESS DATE:		20220303

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:		N-CSR
		SEC ACT:		1940 Act
		SEC FILE NUMBER:	811-01829
		FILM NUMBER:		22706979

	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>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>
<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>f11205d1.htm
<DESCRIPTION>COLUMBIA ACORN TRUST
<TEXT>
Document 1 - file: f11205d1.htm
</DOCUMENT> <DOCUMENT> <TYPE>EX-99.CODE ETH <SEQUENCE>2 <FILENAME>f11205d2.htm <DESCRIPTION>CODE OF ETHICS <TEXT> Document 2 - file: f11205d2.htm
</DOCUMENT> <DOCUMENT> <TYPE>EX-99.CERT <SEQUENCE>3 <FILENAME>f11205d3.htm <DESCRIPTION>SECTION 302 CERTIFICATION <TEXT> Document 3 - file: f11205d3.htm
</DOCUMENT> <DOCUMENT> <TYPE>EX-99.906 CERT <SEQUENCE>4 <FILENAME>f11205d4.htm <DESCRIPTION>SECTION 906 CERTIFICATION <TEXT> Document 4 - file: f11205d4.htm
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>5 <FILENAME>img0b6e5ff49.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 5 - file: img0b6e5ff49.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>6 <FILENAME>img149ee81011.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 6 - file: img149ee81011.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>7 <FILENAME>img2721d8251.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 7 - file: img2721d8251.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>8 <FILENAME>img36128f8e7.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 8 - file: img36128f8e7.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>9 <FILENAME>img6f9baba012.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 9 - file: img6f9baba012.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>10 <FILENAME>img8d6c51b66.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 10 - file: img8d6c51b66.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>11 <FILENAME>imgb8e48ae52.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 11 - file: imgb8e48ae52.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>12 <FILENAME>imgccb59bc24.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 12 - file: imgccb59bc24.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>13 <FILENAME>imgd6d7cd525.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 13 - file: imgd6d7cd525.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>14 <FILENAME>imgdf3cafa03.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 14 - file: imgdf3cafa03.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>15 <FILENAME>imgdf55e0538.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 15 - file: imgdf55e0538.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>16 <FILENAME>imge7c265da10.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 16 - file: imge7c265da10.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>17 <FILENAME>g026023cbr1nzq6646j55.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 17 - file: g026023cbr1nzq6646j55.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>18 <FILENAME>g9mlt1es4ya2gsmuswz5i.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 18 - file: g9mlt1es4ya2gsmuswz5i.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>19 <FILENAME>gcb95pj3c389ne2qtxq49.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 19 - file: gcb95pj3c389ne2qtxq49.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>20 <FILENAME>gepqbc4g7fs0vyx06mkl6.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 20 - file: gepqbc4g7fs0vyx06mkl6.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>21 <FILENAME>gggovpsdqyx7z4gvs4w9y.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 21 - file: gggovpsdqyx7z4gvs4w9y.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>22 <FILENAME>gimainwo4npncnz3ujpn5.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 22 - file: gimainwo4npncnz3ujpn5.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>23 <FILENAME>gp1mqnkk1q1ueszya582l.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 23 - file: gp1mqnkk1q1ueszya582l.jpg
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>24 <FILENAME>gtx283yq8ipqg424m5fr8.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 24 - file: gtx283yq8ipqg424m5fr8.jpg
</DOCUMENT> </SEC-DOCUMENT>