Effect on U.S. Tax Basis

Section 6045B Reporting

United States Internal Revenue Service Circular 230 Disclosure: To ensure compliance with requirements imposed by the IRS, any U.S. tax advice contained in this communication is not intended or written to be used, and cannot be used, for the purpose of (i) avoiding penaria-labelies under the Internal Revenue Code or (ii) promoting, marketing or recommending to another party any transaction or matter addressed herein.

Purpose:

Section 6045B of the Internal Revenue Code of 1986, as amended (“Code”), requires an issuer of stock to provide to the United States Internal Revenue Service (“IRS”) and to the holders of stock certain information on organizational actions that affect the tax basis of such stock for United States federal income tax purposes. Under Treasury Regulation § 1.6045B-1(a)(3) and (b)(4), an issuer may comply with these requirements by posting such information on its public Web site.

Issuer:

Commerce Bancshares, Inc. (NASDAQ - CBSH)

Description of Organizational Action:

Please see attached Forms 8937 which report organizational actions affecting basis of securities which is required for issuers of a specified security (including any share of stock in an entity organized as, or treated for federal tax purposes as, a corporation, or any interest treated as stock). Form 8937 includes: quantitative effect on the basis of the security; the calculation of the change in basis; and the data that supports the calculation and lists Internal Revenue Code sections and subsections upon which the tax treatment is based.