2008 Annual Cash Bonus Awards
   On November 18, 2008, the Compensation Committee of the Board of Directors of
Maxygen, Inc. (the "Company") approved annual cash bonuses for the executive
officers of the Company for 2008 in the following amounts:


        Name                                                 Bonus Amount
        Russell J. Howard                                    $    200,000
        Chief Executive Officer
        Elliot Goldstein                                     $     98,961
        Chief Operating Officer
        Lawrence W. Briscoe                                  $     88,314
        Chief Financial Officer and Senior Vice President
        Grant Yonehiro                                       $    102,100
        Chief Business Officer and Senior Vice President

Under the Company's annual cash bonus plan for executive officers, the Board previously established target bonus amounts and performance goals for 2008, with 80% of the target amount based on the achievement of certain strategic objectives and the remaining 20% of the target amount discretionary. Based on its evaluation of these targets and objectives, the Compensation Committee awarded each executive officer a portion of the bonus amount attributable to the achievement of certain strategic objectives and the full amount of the discretionary component. The Compensation Committee also used its discretionary authority to award additional bonus amounts to Dr. Howard and Mr. Yonehiro to recognize their contributions to the achievement of corporate objectives that were not included in the previously established goals. The bonus payments will be paid to each executive officer in one payment on or about December 31, 2008.