SecProbe.io

August 2 4, 2012

Via E -mail
James L. Swarts
Vice President and Secretary
Commerce Bancshares, Inc.
1000 Walnut Street
Kansas City, MO

Re: Commerce Bancshares, Inc
Form 10-K for the Fiscal Year Ended December 31, 2011
Filed February 22, 2012
Form 10 -Q for the Quarterly Period Ended March 31, 2012
Filed May 4 , 2012
 File No. 000-02989

Dear Mr. Swarts :

We have reviewed your filing s and have the following comments.  In some of our
comments, we may ask you to provide us with information so we may b etter understand your
disclosure.

Please respond to this letter within ten business days by amending your filing s, by
providing the requested information, or by advising us when you will provide the requested
response.   Where we have requested changes in future filings, please include a draft of your
proposed dis closures that clearly identifies  new or revised disclosures.  If you do not believe our
comments apply to your facts and circumstances or do not believe an amendment is appropriate,
please tell us why in your response.

After reviewing any amendment s to your filing s and the information you provide in
response to these  comments,  including the draft of your proposed disclosures,  we may have
additional comments.

Form 10 -K for the Fiscal  Year Ended December 31, 2011

Notes to Consolidated Financial Statements
Note 2 – Loans and Allowance for Loan Losses, page 67
Troubled Debt Restructurings, page 72

1. We note your disclosure that the majority of your troubled debt restructurings are
classified as such upon renewal when the contractual interest rate of the new loan was not

James L. Swarts
Commerce Bancshares, Inc.
August 2 4, 2012
Page 2

 judged to be a market rate for debt with similar risk , and that the financial effects of the
modifications cannot readily be quantified.  Please explain why you cannot quantify the
financial effect of the modi fications (i.e. additional allowances for credit losses, principal
amounts charged off, foregone interest , etc. ) as required by ASC 310 -10-50-33(a).

Note 15  - Fair Value Measurements, page 94
Derivatives, page 96

2. We note your disclosure that the impact of credit standing is considered in determining
the fair value o f your derivative instruments.  In the interest of transparency, please revise
your disclosure in future filings to more clearly explain how yo u fact or both your own
and counterparty credit risk into your fair value determinations for your derivative
instruments (i.e., explain how these credit valuation adjustments are calculated).

Note 16 - Fair Value of Financial Instruments, page 101
Loans, page 101
3. You disclose that your method for estimating the fair values of loans does not incorporate
the exit  price concept of fair value prescribed by ASC 820 "Fair Value Measurement".
Please explain why you believe it is appropriate not to use the exit price as the
measurement of fair value as required by ASC 820 -10-35-9A.

Form 10 -Q for the Quarte rly Period  Ended March 31 , 2012
Note 12 – Fair Value Measurements, page 26
Level 3 Inputs, page 30
4. We note that you have classified certain assets and liabilities measured at fair value on a
recurring and non -recurring basis as Level 3 in the fair value hierarchy, including auction
rate securities, private equity investments, certain loans, mortgage servicing rights,
foreclosed and long lives assets.  However, we we re unable to locate a description of the
valuation processes used (for example, how an entity decides its policies and procedures
and analyzes changes in measurements from period to period) as required by ASC 820 -
10-50-2-f and 820 -10-55-105.  Please revise  your future filings to provide these
disclosures.

Valuation methods for instruments measured at  fair value on a nonrecurring basis, page 31
5. We note that you classified certain loans, mortgage servicing rights, foreclosed and long -
lived assets measured at fair valued on a non -recurring basis as Level 3 in the fair va lue
hierarchy.  However, we unable to locate any quantitative disclosures about the
significant unobservable inputs used in these fair value measurements as required by
ASC 820 -10-50-2-bbb.  Please revise your future filings to provide these disclosures.

James L. Swarts
Commerce Bancshares, Inc.
August 2 4, 2012
Page 3

              We urge all persons who are responsible for the accuracy and adequacy of the disclosure
in the filing to be certain that the filing includes the information the Securities Exchange Act of
1934 and all applicable Exchange Act rules require.   Since the company and its management are
in possession of all facts relating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they have made.

            In responding to our comments, please provide  a wri tten statement from the company
acknowledging that:

 the company is responsible for the adequacy and accuracy of the disclosure in the filing;

 staff comments or changes to disclosure in response to staff comments do not foreclose
the Commission from takin g any action with respect to the filing; and

 the company may not assert staff comments as a defense in any proceeding initiated by
the Commission or any person under the federal securities laws of the United States.

You may contact Sasha Pechenik  at (202) 551 -3541  or me, at (202) 551 -3872 if you have
any questions .

Sincerely,

 /s/ Hugh West

Hugh West
Accounting Branch Chief