FORM OF SECTION 906 CERTIFICATION EX-99.906CERT MAIL Michael S. Daubs, President, and Mary E. Hoffmann, Treasurer, of Ultra Series Fund (the "Registrant"), to the best of their knowledge, each certify that: 1. The Registrant's periodic report on Form N-CSR for the period ended December 31, 2005 (the "Form N-CSR") fully complies with the requirements of Section 15(d) of the Securities Exchange Act of 1934, as amended; and 2. The information contained in the Form N-CSR fairly presents, in all material respects, the financial condition and results of operations of the Registrant. PRESIDENT TREASURER /s/ Michael S. Daubs /s/ Mary E. Hoffmann - ------------------------------------- ---------------------------------------- Michael S. Daubs Mary E. Hoffmann Date: February 20, 2006 Date: February 21, 2006