[Ropes & Gray LLP Letterhead]

                                          June 5, 2006

Columbia Mid Cap Growth Fund
c/o Columbia Funds Series Trust I
One Financial Center
Boston, Massachusetts 02111-2621

     Re: Registration Statement on Form N-14

Ladies and Gentlemen:

   We have acted as counsel to Columbia Midcap Growth Fund (the "Acquiring
Fund"), a series of Columbia Funds Series Trust I (the "Trust"), in connection
with the registration statement of the Trust on Form N-14 (the "Registration
Statement") being filed by the Trust under the Securities Act of 1933, as
amended (the "Act"), relating to the proposed combination of the Acquiring Fund
with Columbia Marsico Mid Cap Growth Fund (the "Acquired Fund"), a series of
Columbia Funds Series Trust ("Series Trust"), and the issuance of Class A,
Class B, Class C and Class Z shares of beneficial interest of the Acquiring
Fund in connection therewith (the "Shares"), all in accordance with the terms
of the Agreement and Plan of Reorganization by and among the Trust, on behalf
of the Acquiring Fund and other acquiring funds listed therein, Series Trust,
on behalf of the Acquired Fund and other acquired funds listed therein, and
Columbia Management Advisors, LLC (the "Agreement and Plan of Reorganization"),
in substantially the form included in the Registration Statement.

   We have examined the Trust's Agreement and Declaration of Trust on file in
the office of the Secretary of the Commonwealth of Massachusetts (the
"Declaration of Trust") and the Trust's Bylaws, both as amended to date, and
are familiar with the actions taken by the Trust's trustees in connection with
the issuance and sale of the Shares. We have also examined such other documents
and records as we have deemed necessary for the purposes of this opinion.

   We have assumed for purposes of this opinion that, prior to the date of the
issuance of the Shares, (1) the trustees of the Trust will have taken all
actions required of



them for the approval of the Agreement and Plan of Reorganization, and (2) the
trustees of Series Trust, on behalf of the Acquired Fund, will have taken all
actions required of them for approval of the Agreement and Plan of
Reorganization, and (3) the Agreement and Plan of Reorganization will have been
duly executed and delivered by each party thereto.

   Based upon the foregoing, we are of the opinion that:

   1. The Trust is a duly organized and validly existing unincorporated
association under the laws of the Commonwealth of Massachusetts and is
authorized to issue an unlimited number of its shares of beneficial interest.

   2. When issued in accordance with the Agreement and Plan of Reorganization,
the Shares will be validly issued, fully paid and, except as noted in the
paragraph below, nonassessable by the Trust.

   The Trust is an entity of the type commonly known as a "Massachusetts
business trust." Under Massachusetts law, shareholders could, under certain
circumstances, be held personally liable for the obligations of the Trust.
However, the Declaration of Trust disclaims shareholder liability for acts or
obligations of the Trust and requires that a notice of such disclaimer be given
in each note, bond, contract, instrument, certificate or undertaking entered
into or executed by the Trust or its trustees. The Declaration of Trust
provides that in case any shareholder or former shareholder shall be held to be
personally liable solely by reason of his or her being or having been a
shareholder and not because of his or her acts or omissions or for some other
reason, the shareholder or former shareholder (or his or her heirs, executors,
administrators or other legal representatives or, in the case of a corporation
or other entity, its corporate or other general successor) shall be entitled to
be held harmless from and indemnified against all loss and expense arising from
such liability. Thus, the risk of a shareholder's incurring financial loss on
account of shareholder liability is limited to circumstances in which the Trust
would be unable to meet its obligations.

                                                  Very truly yours,

                                                  /s/ Ropes & Gray LLP