Columbia Acorn Trust
                Amended and Restated Rule 12b-1 Distribution Plan

      Columbia Acorn Trust (the Trust) hereby adopts the following distribution
plan (the Plan) pursuant to Rule 12b-1 (the Rule) under the Investment Company
Act of 1940 (the Act) on behalf of each Fund in the Trust designated in Appendix
I, for the purpose of providing personal service and/or the maintenance of
shareholder accounts and to facilitate the distribution of shares of the Funds.
This Plan applies only to the Class A, Class B or Class C shares of each Fund.

I.    Plan Applying to Class A, B and C Shares

      Each Fund having Class A, B, or C shares shall pay a service fee at the
annual rate of 0.25% of the net assets of its Class A, B, or C shares, and a
distribution fee at the annual rate of 0.60% of the average daily net assets of
its Class B shares and 0.75 % of the average daily net assets of its Class C
shares. Amounts payable under this paragraph are subject to any limitations on
such amounts prescribed by applicable laws or rules.

II.   Payments of Fees Under the Plan

      Each Fund shall make all payments of service and distribution fees under
this Plan to Columbia Funds Distributor, Inc. (CFDI) monthly, on the 20th day of
each month or, if such day is not a business day, on the next business day
thereafter. No Fund shall pay, nor shall CFDI be entitled to receive, any amount
under this Plan if such payment would result in CFDI receiving amounts in excess
of those permitted by applicable law or by rules of the National Association of
Securities Dealers, Inc.

III.  Use of Fees

      CFDI may pay part or all of the service and distribution fees it receives
from a Fund as commissions to financial service firms that sell Fund shares or
as reimbursements to financial service firms or other entities that provide
shareholder services to record or beneficial owners of shares (including
third-party administrators of qualified plans). This provision does not obligate
CFDI to make any such payments nor limit the use that CFDI may make of the fees
it receives.

IV.   Reporting

      CFDI shall provide to the Trust's Trustees, and the Trustees shall review,
at least quarterly, reports setting forth all Plan expenditures, and the
purposes for those expenditures.

V.    Other Payments Authorized

      Payments by the Trust to CFDI and its affiliates other than as set forth
in Section I which may be indirect financing of distribution costs of Class A,
Class B, or Class C shares are authorized by this Plan.





VI.   Effective Date

      This Plan shall be effective on August 1, 2004.

VII.  Continuation; Amendment; Termination

      This Plan shall continue in effect with respect to Class A, Class B and
Class C shares only so long as specifically approved for that class at least
annually as provided in the Rule. The Plan may not be amended to increase
materially the service fee or distribution fee with respect to a class of shares
without such shareholder approval as is required by the Rule and any applicable
orders of the Securities and Exchange Commission, and all material amendments of
the Plan must be approved in the manner described in the Rule. The Plan may be
terminated with respect to any class of shares at any time as provided in the
Rule without payment of any penalty. The continuance of the Plan shall be
effective only if the selection and nomination of the Trust's Trustees who are
not interested persons (as defined under the Act) of the Trust is effected by
such non-interested Trustees as required by the Rule.

                                  Approved by the Trustees as of August 1, 2004.


                                  By: /s/ Robert Nason
                                      -----------------------------------





APPENDIX I

Columbia Acorn Fund
Columbia Acorn International
Columbia Acorn USA
Columbia Acorn Select
Columbia Acorn International Select
Columbia Thermostat Fund



Dated August 1, 2004