COLUMBIA TAX-EXEMPT INSURED FUND
                                  (THE "FUND")

                SUPPLEMENT TO THE PROSPECTUS DATED MARCH 27, 2006

         The Board of Trustees of the Fund has approved a proposal to reorganize
the Fund into Columbia Tax-Exempt Fund (the "Acquiring Fund"), subject to
approval by the shareholders of the Fund. If the shareholders of the Fund
approve the proposal relating to the reorganization of the Fund, and the
various other conditions to the closing of the reorganization are satisfied, all
of the assets of the Fund will be transferred to the Acquiring Fund and
shareholders of the Fund will receive shares of the Acquiring Fund in exchange
for their shares. Shareholders of the Fund are scheduled to vote on the proposal
relating to the reorganization of their Fund at a special meeting of
shareholders currently expected to be held in the third quarter of 2006. If
approved at the special meeting, the reorganization is proposed to take place
shortly thereafter.

         The foregoing is not an offer to sell, nor a solicitation of an offer
to buy, shares of the Acquiring Fund, nor is it a solicitation of any proxy. For
more information regarding the Acquiring Fund, or to receive a free copy of a
prospectus/proxy statement relating to a proposed reorganization once a
registration statement relating to the proposed reorganizations has been filed
with the Securities and Exchange Commission and become effective, please call
1-800-345-6611 or visit the Fund's website at www.columbiafunds.com. This
prospectus/proxy statement (when available) will contain important information
about fees, expenses and risk considerations. The prospectus/proxy statement
will also be available for free on the Securities and Exchange Commission's
website (www.sec.gov). Please read the prospectus/proxy statement carefully
before making any investment decisions.



INT-47/109558-0406                                                April 25, 2006