Confirming Statement

This statement confirms that the undersigned has authorized and designated
James L. Swarts and Jeffery D. Aberdeen or either of them to execute and
file on the undersigned's behalf all Forms 3, 4, and 5 (including any
amendments thereto) that the undersigned may be required to file with the
Securities and Exchange Commission as a result of the undersigned's ownership
of or transactions in securities of Commerce Bancshares, Inc.  The authority
of James L. Swarts and Jeffery D. Aberdeen under this statement shall continue
until the undersigned is no longer required to file Forms 3, 4, and 5 with
regard to the undersigned's ownership of or transactions in securities of
Commerce Bancshares, Inc., unless earlier revoked in writing.  The undersigned
acknowledges that neither James L. Swarts nor Jeffery D. Aberdeen is assuming
any of the undersigned's responsiblities to comply with Section 16 of the
Securities Exchange Act of 1934.


Date Elected:	April 21, 2010			/s/ Earl H. Devanny
						Earl H. Devanny