COLUMBIA ACORN TRUST

               Amended and Restated Plan pursuant to Rule 18f-3(d)
                    under the Investment Company Act of 1940


Each Series (each a "Columbia Acorn Fund") of Columbia Acorn Trust (the "Trust")
as set forth in Schedule I may from time to time issue one or more of the
following classes of shares as authorized by the Board of Trustees and as
provided for herein: Class A shares, Class B shares, Class C shares and Class Z
shares. Each class is subject to such investment minimums and other conditions
of eligibility as are set forth in the Trust's prospectus and statement of
additional information for shares of that class as from time to time in effect.
The differences in expenses among these classes of shares and the conversion and
exchange features of each class of shares are set forth below. These differences
are subject to change, to the extent permitted by law and by the Declaration of
Trust and By-laws of the Trust, by action of the Board of Trustees. This Plan,
as amended and restated, shall be effective as of August 1, 2004.

CLASS A SHARES

Class A shares of each Columbia Acorn Fund are offered at net asset value
("NAV") plus the initial sales charges described in the Trust's prospectus and
statement of additional information for Class A shares as from time to time in
effect. Initial sales charges may not exceed 6.50%, and may be reduced or waived
as permitted by Rule 22d-1 under the Investment Company Act of 1940 (the "1940
Act") and as described in the Trust's prospectus and statement of additional
information for Class A shares from time to time in effect.

Purchases of $1 million to $5 million of Class A shares that are redeemed within
18 months from purchase are subject to a contingent deferred sales charge
("CDSC") of 1.00% of either the purchase price or the NAV of the shares
redeemed, whichever is less. Purchases in excess of $5 million of Class A shares
that are redeemed within 18 months from purchase are subject to a CDSC of 1.00%
only on assets redeemed below the $5 million level. The CDSC may be reduced or
waived in certain circumstances as permitted by Rule 6c-10 under the 1940 Act
and as described in the Trust's prospectus and statement of additional
information for Class A shares as from time to time in effect.

Class A shares pay a service fee pursuant to a plan adopted pursuant to Rule
12b-1 under the 1940 Act ("12b-1 Plan") as described in the Trust's prospectus
and statement of additional information for Class A shares in effect from time
to time. Such fee may be in an amount up to but may not exceed 0.25% per annum
of the average daily net assets attributable to such class.

Class A shares pay all transfer agency fees and expenses, and any other
expenses, specifically allocable to Class A shares

Class A shares of a Columbia Acorn Fund may be exchanged, at the holder's
option, for Class A shares of any other fund (each, including each Columbia
Acorn Fund, a "Columbia Fund" and



together, "Columbia Funds") distributed by Columbia Funds Distributor, Inc.
("CFDI") or its successor, which offers Class A shares, without the payment of a
sales charge, except to the extent such an exchange is limited by the Trust's
prospectus for Class A shares as from time to time in effect and except further
that if Class A shares of any non-money market Columbia Fund are exchanged
within five months after purchase for shares of another Columbia Fund with a
higher sales charge, then the difference in sales charges must be paid on the
exchange.

No CDSC shall be charged on the exchange of Class A shares of a Columbia Acorn
Fund for Class A shares of another Columbia Fund. If the Class A shares received
in the exchange are subsequently redeemed, the amount of the CDSC, if any, will
be determined by the schedule of the Columbia Fund in which the original
investment was made, and the holding period for determining the CDSC will
include the holding period of the shares exchanged.

CLASS B SHARES

Class B shares of each Columbia Acorn Fund are offered at NAV, without an
initial sales charge. Class B shares that are redeemed within the period of time
after purchase (not more than 6 years) specified in the Trust's prospectus and
statement of additional information for Class B shares as from time to time in
effect are subject to a CDSC of up to 5% of either the purchase price or the NAV
of the shares redeemed, whichever is less; such percentage may be lower for
certain Funds and declines the longer the shares are held, all as described in
the Trust's prospectus and statement of additional information for Class B
shares as from time to time in effect. Class B shares purchased with reinvested
distributions are not subject to a CDSC. The CDSC may be reduced or waived in
certain circumstances, as permitted by Rule 6c-10 under the 1940 Act and as
described in the Trust's prospectus and statement of additional information for
Class B shares as from time to time in effect.

Class B shares pay distribution and service fees pursuant to a 12b-1 Plan as
described in the Trust's prospectus and statement of additional information for
Class B shares in effect from time to time. Such fees may be in amounts up to
but may not exceed, respectively, 0.60% and 0.25% per annum of the average daily
net assets attributable to such class.

Class B shares pay all transfer agency fees and expenses, and any other
expenses, specifically allocable to Class B shares.

Class B shares of a Columbia Acorn Fund automatically convert to Class A shares
of the same Columbia Acorn Fund eight or fewer years after purchase, except that
Class B shares purchased through the reinvestment of dividends and other
distributions on Class B shares convert to Class A shares proportionally to the
amount of Class B shares otherwise being converted.

Class B shares of a Columbia Acorn Fund may be exchanged, at the holder's
option, for Class B shares of any other Columbia Fund offering Class B shares,
except to the extent such an exchange is limited by the Trust's prospectus as
from time to time in effect, without the payment of a CDSC. The holding period
for determining the CDSC and the conversion to Class A shares for the Class B
shares received in the exchange will include the holding period of the shares
exchanged. If the Class B shares received in the exchange are subsequently
redeemed, the


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amount of the CDSC, if any, will be determined by the schedule of the Columbia
Fund in which the original investment was made.

CLASS C SHARES

Class C shares of each Columbia Acorn Fund are offered at NAV without an initial
sales charge. Class C shares that are redeemed within three years from purchase
may be subject to a CDSC of 1% of either the purchase price or the NAV of the
shares redeemed, whichever is less. Class C shares purchased with reinvested
dividends or capital gain distributions are not subject to a CDSC. The CDSC may
be reduced or waived in certain circumstances as permitted by Rule 6c-10 under
the 1940 Act and as described in the Trust's prospectus and statement of
additional information for Class C shares as from time to time in effect.

Class C shares pay distribution and service fees pursuant to a 12b-1 Plan as
described in the Trust's prospectus and statement of additional information for
Class C shares in effect from time to time. Such fees may be in amounts up to
but may not exceed, respectively, 0.75% and 0.25% per annum of the average daily
net assets attributable to such class.

Class C shares pay all transfer agency fees and expenses, and any other
expenses, specifically allocable to Class C shares.

Class C shares of a Columbia Acorn Fund may be exchanged, at the holder's
option, for Class C shares of any other Columbia Fund offering Class C shares,
except to the extent such an exchange is limited by the Trust's prospectus for
Class C shares as from time to time in effect, without the payment of a CDSC. If
the Class C shares received in the exchange are subsequently redeemed, the
amount of the CDSC, if any, will be determined by the schedule of the Columbia
Fund in which the original investment was made, and the holding period for
determining the CDSC will include the holding period of the shares exchanged.
Only one exchange of any Columbia Fund Class C shares may be made in any
three-month period. For this purpose, an exchange into a Columbia Fund and a
prior or subsequent exchange out of a Columbia Fund constitute an "exchange."

CLASS Z SHARES

Class Z shares of each Columbia Acorn Fund are offered at NAV, without an
initial sales charge, 12b-1 fee or CDSC. Class Z shares of a Columbia Acorn Fund
may be exchanged, at the holder's option, for Class Z shares of any other
Columbia Fund offering Class Z shares or for Class A shares of any other
Columbia Fund not offering Class Z shares and offering Class A shares, except to
the extent such exchange is limited by the Trust's prospectus for Class Z shares
as from time to time in effect, without the payment of a sales charge. Class Z
shares pay all transfer agency fees and expenses, and any other expenses,
specifically allocable to Class Z shares.

                        Approved by the Trustees as of August 1, 2004

                        By: /s/ Robert Nason
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SCHEDULE I

Columbia Acorn Fund

Columbia Acorn International

Columbia Acorn USA

Columbia Acorn Select

Columbia Acorn International Select

Columbia Thermostat Fund





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