497 1 classb.txt CLASS B DEALER REALLOWANCE COLUMBIA ACORN TRUST Supplement dated July 1, 2004 To Class A, B and C Share Prospectuses Dated May 1, 2004 of Columbia Acorn Fund Columbia Acorn International Columbia Acorn USA Columbia Acorn Select Columbia Acorn International Select Columbia Thermostat Fund Effective July 1, 2004, the table for sales charges for Class B shares for purchases of less than $250,000, and the first paragraph following that table under the heading "Your Account--Sales Charges" are being replaced in their entirety by the following:
Purchases of less than $250,000: Class B Sales Charges % deducted when Holding period after purchase shares are sold Through first year 5.00 Through second year 4.00 Through third year 3.00 Through fourth year 3.00 Through fifth year 2.00 Through sixth year 1.00 Longer than six years 0.00
Up-front commission to financial advisors is 4.00% and is paid by the distributor. From the 12b-1 annual fee of 1.00% paid out of your Fund assets, the distributor retains 0.75%, and your financial advisor is paid the remaining 0.25% as an ongoing commission. ACN-36/288S-0704 July 1, 2004