Exhibit 21 The consolidated subsidiaries of the Registrant at March 1, 1999, were as follows: State or Other Jurisdiction of Name Location Incorporation Commerce Bank, National Association Kansas City, MO United States CB Building Corp. Kansas City, MO Missouri Tower Redevelopment Corporation Kansas City, MO Missouri Twin City Development Company, Inc. Kansas City, KS Kansas Commerce Financial Corp. Clayton, MO Missouri Commerce Realty Corp. Clayton, MO Missouri County Realty Corp. Clayton, MO Missouri Commerce Brokerage Services, Inc. Clayton, MO Missouri Clayton Financial Corp. Clayton, MO Missouri Clayton Realty Corp. Clayton, MO Missouri Commerce Insurance Services, Inc. Fenton, MO Missouri Commerce Bank of Omaha, National Association Omaha, NE United States Commerce Bank, National Association Peoria, IL United States Commerce Bank, National Association Wichita, KS United States Union Center, Inc. Wichita, KS Kansas 21st Street Redevelopment Company, L.C. Wichita, KS Kansas City National Bank Pittsburg, KS United States The Citizens National Bank in Independence Independence, KS United States Columbus State Bank Columbus, KS Kansas Mid-America Financial Corp. Kansas City, MO Missouri Delaware Redevelopment Corporation Kansas City, MO Missouri CBI Insurance Company Kansas City, MO Arizona Capital for Business, Inc. Kansas City, MO Missouri Commerce Property and Casualty Agency, Inc. Kansas City, MO Missouri Commerce Mortgage Corp. Kansas City, MO Missouri CFB Venture Fund I, Inc. Clayton, MO Missouri CFB Partners, Inc. Kansas City, MO Missouri UBI Financial Services, Inc. Wichita, KS Kansas CBI-Illinois, Inc. Kansas City, MO Delaware CBI-Kansas, Inc. Kansas City, MO Kansas Shawnee State, Inc. Shawnee, KS Kansas