EX-99.77B ACCT LTTR

                                                                    Exhibit 77B

            Report of Independent Registered Public Accounting Firm

To the Board of Trustees and Shareholders of Columbia Acorn Trust:

In planning and performing our audit of the financial statements of Columbia
Acorn Fund, Columbia Acorn International, Columbia Acorn USA, Columbia Acorn
International Select, Columbia Acorn Select, Columbia Thermostat Fund, Columbia
Acorn Emerging Markets Fund, and Columbia Acorn European Fund (the "Funds") as
of and for the year ended December 31, 2012, in accordance with the standards
of the Public Company Accounting Oversight Board (United States), we considered
the Funds' internal control over financial reporting, including controls over
safeguarding securities, as a basis for designing our auditing procedures for
the purpose of expressing our opinion on the financial statements and to comply
with the requirements of Form N-SAR, but not for the purpose of expressing an
opinion on the effectiveness of the Funds' internal control over financial
reporting. Accordingly, we do not express an opinion on the effectiveness of
the Funds' internal control over financial reporting.

The management of the Funds is responsible for establishing and maintaining
effective internal control over financial reporting. In fulfilling this
responsibility, estimates and judgments by management are required to assess
the expected benefits and related costs of controls. A fund's internal control
over financial reporting is a process designed to provide reasonable assurance
regarding the reliability of financial reporting and the preparation of
financial statements for external purposes in accordance with generally
accepted accounting principles. A fund's internal control over financial
reporting includes those policies and procedures that (1) pertain to the
maintenance of records that, in reasonable detail, accurately and fairly
reflect the transactions and dispositions of the assets of the fund;
(2) provide reasonable assurance that transactions are recorded as necessary to
permit preparation of financial statements in accordance with generally
accepted accounting principles, and that receipts and expenditures of the Fund
are being made only in accordance with authorizations of management and
trustees of the fund; and (3) provide reasonable assurance regarding prevention
or timely detection of unauthorized acquisition, use or disposition of a fund's
assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting
may not prevent or detect misstatements. Also, projections of any evaluation of
effectiveness to future periods are subject to the risk that controls may
become inadequate because of changes in conditions, or that the degree of
compliance with the policies or procedures may deteriorate.

A deficiency in internal control over financial reporting exists when the
design or operation of a control does not allow management or employees, in the
normal course of performing their assigned functions, to prevent or detect
misstatements on a timely basis. A material weakness is a deficiency, or a
combination of deficiencies, in internal control over financial reporting, such
that there is a reasonable possibility that a material misstatement of the
Funds' annual or interim financial statements will not be prevented or detected
on a timely basis.

Our consideration of the Funds' internal control over financial reporting was
for the limited purpose described in the first paragraph and would not
necessarily disclose all deficiencies in internal control over financial
reporting that might be material weaknesses under standards established by the
Public Company Accounting Oversight Board (United States). However, we noted no
deficiencies in the Funds' internal control over financial reporting and its
operation, including controls over safeguarding securities that we consider to
be material weaknesses as defined above as of December 31, 2012.

This report is intended solely for the information and use of management and
the Board of Trustees of the Funds and the Securities and Exchange Commission
and is not intended to be and should not be used by anyone other than these
specified parties.

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP
Chicago, Illinois
February 22, 2013

PricewaterhouseCoopers LLP, One North Wacker Drive Chicago, IL,60606
T: (312) 298 2000, F: (312) 298 2001, www.pwc.com/us

EX-99.77D POLICIES

                                                                    Exhibit 77D

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Item 77D/77Q1(b) - Policies with Respect to Securities Investments:

On December 10, 2012, Form Type 497, Accession No. 0001193125-12-496220 , a
supplement to the registration statement of Columbia Acorn Trust on behalf of
Columbia Thermostat Fund was filed with the SEC. It is hereby incorporated by
reference as part of the response to these Items 77D and 77Q1(b) of Form N-SAR.
The supplement made material changes to the disclosure in the Principal
Investment Strategies section of the Columbia Thermostat Fund's prospectuses to
make certain changes to the underlying bond funds in which it invests (the
"Portfolio Funds"). Specifically, the investment adviser has removed Columbia
U.S. Treasury Index Fund and added Columbia Short Term Bond Fund at a weighting
of 40% among the bond Portfolio Funds. The investment adviser has also reduced
the weighting of Columbia Intermediate Bond Fund from 50% to 30% among the bond
Portfolio Funds.

EX-99.77E LEGAL

                                                                    Exhibit 77E

Item 77E - Legal Proceedings:

Ameriprise Financial and certain of its affiliates have historically been
involved in a number of legal, arbitration and regulatory proceedings,
including routine litigation, class actions, and governmental actions,
concerning matters arising in connection with the conduct of their business
activities. Ameriprise Financial believes that the Funds are not currently the
subject of, and that neither Ameriprise Financial nor any of its affiliates are
the subject of, any pending legal, arbitration or regulatory proceedings that
are likely to have a material adverse effect on the Fund or the ability of
Ameriprise Financial or its affiliates to perform under their contracts with
the Funds Ameriprise Financial is required to make 10-Q, 10-K and, as
necessary. 8-K filings with the Securities and Exchange Commission on legal and
regulatory matters that relate to Ameriprise Financial and its affiliates
Copies of these filings may be obtained by accessing the SEC website at
www.sec.gov.

There can be no assurance that these matters, or the adverse publicity
associated with them, will not result in increased fund redemptions, reduced
sale of fund shares or other adverse consequences to the Funds. Further,
although we believe proceedings are not likely to have a material adverse
effect on the Funds or the ability of Ameriprise Financial or its affiliates to
perform under their contracts with the Funds, these proceedings are subject to
uncertainties and, as such, we are unable to estimate the possible loss or
range of loss that may result. An adverse outcome in one or more of these
proceedings could result in adverse judgments, settlements, fines, penalties or
other relief that could have a material adverse effect on the consolidated
financial condition or results of operations of Ameriprise Financial.

EX-99.77I NEW SECUR

                                                                    Exhibit 77I

Item 77I/77Q1(d) - Terms of new or amended securities:

An Amended and Restated Multi-Class Plan, pursuant to Rule 18f-3(d), for the
Funds dated September 7, 2010, amended on November 8, 2012 is incorporated by
reference to Post-Effective Amendment No. 95 to the Registration Statement of
the Registrant on Form Type 485BPOS filed on November 7, 2012, Accession No.
001193125-12-457520.

                                     *****

Changes to Class A and Class Z shares of each of the Funds and features of
Class R5 shares of Columbia Acorn International, as described in the supplement
to the prospectus(es) and Statement of Additional Information of each of the
Funds, dated and filed October 1, 2012 pursuant to Rule 497(e) of the
Securities Act of 1933, Accession No. 0001193125-12-410394, are incorporated by
reference.

Certain features of Class A and Class Z shares of each of the Funds and
features of Class R5 shares of Columbia Acorn International were changed, as
described below:

1. Changes to Class R5 - Re-opening; Eligibility. Effective November 8, 2012,
   Class R5 shares of Columbia Acorn International are available for purchase
   by (i) registered investment advisers that clear Fund share transactions for
   their client or customer accounts through designated mutual fund trading
   platforms that have been granted specific written authorization from the
   Funds' transfer agent with respect to Class R5 eligibility apart from
   selling, servicing or similar agreements and (ii) omnibus retirement plans.
   Existing shareholders who do not satisfy the new eligibility requirements
   for investment in Class R5 shares may not establish new Class R5 accounts,
   but may continue to make additional purchases of Class R5 shares in accounts
   opened and funded prior to November 8, 2012. In addition, investment
   advisory programs and similar programs that opened a Class R5 account as of
   May 1, 2010, and continuously hold Class R5 shares in such account after
   such date, may generally not only continue to make additional purchases of
   Class R5 shares but also open new Class R5 accounts and add new shareholders
   in the program. Prior to November 8, 2012, Class R5 shares were closed to
   new investors and new accounts, subject to certain exceptions.

2. Changes to Class Z - Partial Closing.

    A. Omnibus Retirement Plans. Effective March 29, 2013, omnibus retirement
       plans are not permitted to establish new Class Z accounts, subject to
       the following exceptions. Omnibus retirement plans that opened and
       funded a Class Z account with the Fund as of the close of business on
       March 28, 2013, and continuously hold Class Z shares in such account
       after March 28, 2013, may continue to make additional purchases of Class
       Z shares, open new Class Z accounts and add new participants. In
       addition, an omnibus retirement plan may, in the discretion of the
       Funds' distributor, open new Class Z accounts for a Fund after March 28,
       2013 if the plan's sponsor or an affiliated sponsor opened and funded a
       Class Z account for another omnibus retirement plan as of the close of
       business on March 28, 2013. If an omnibus retirement plan invested in
       Class Z shares changes recordkeepers after March 28, 2013, any new
       accounts established for that plan may not be established in Class Z
       shares but such a plan may establish new accounts in a different share
       class for which the plan is eligible.

    B. Selling Agents that Clear through Certain Platforms. Effective March 29,
       2013, accounts of selling agents (other than omnibus retirement plans,
       discussed above) that clear Fund share transactions for their client or
       customer accounts through designated mutual fund trading platforms that
       have been given specific written notice from the Fund's transfer agent
       of the termination of their eligibility for new purchases of Class Z
       shares will not be permitted to establish new Class Z accounts or make
       additional purchases of Class Z shares for existing accounts (other than
       through reinvestment of distributions).

    C. Other Existing Class Z Shareholders. Existing holders of Class Z shares
       (other than those described in the immediately preceding paragraph) may
       continue to maintain Class Z accounts and make additional purchases of
       Class Z shares (including through reinvestment of distributions).

3. Exchangeability. Shareholders may exchange shares of one share class of a
   Fund for shares of another share class of the Fund or another fund managed
   by Columbia Wanger Asset Management, LLC or its affiliates, subject to
   eligibility. Before making such an exchange, you should consider the fees
   and expenses of each share class.

4. Front-End Sales Charge Waivers for Class A Shares. Effective November 8,
   2012, the Funds' distributor may waive front-end sales charges on
   (i) purchases (including exchanges) of Class A shares in accounts of selling
   agents that have entered into agreements with the Funds' distributor to
   offer Fund shares to self-directed investment brokerage accounts that may or
   may not charge a transaction fee to customers and (ii) exchanges of Class Z
   shares of a Fund for Class A shares of the Fund.

                                     *****



On November 7, 2012, a Form Type 485(b), Accession No. 0001193125-12-457520, an
amendment to the registration statement of Columbia Acorn Trust, was filed with
the SEC. This amendment registered new classes of shares of the Funds listed
below, effective November 8, 2012, and describes the characteristics of the new
classes of shares:



Fund                                          New Share Class(es)
----                                          -------------------
                                           
Columbia Acorn Emerging Markets Fund                R4, R5
Columbia Acorn European Fund                          R4
Columbia Acorn Fund                                R4, R5, Y
Columbia Acorn International                         R4, Y
Columbia Acorn International Select                R4, R5, Y
Columbia Acorn Select                              R4, R5, Y
Columbia Acorn USA                                 R4, R5, Y
Columbia Thermostat Fund                           R4, R5, Y