Cal. Business and Professions Code § 2184

(a) Each applicant shall obtain on the written examination a passing score, established by the board pursuant to Section 2177. (b) (1) Passing scores on each step of the United States Medical Licensing Examination shall be valid for a period of 10 years from the month of the examination for purposes of qualification for licensure in California. (2) The period of validity provided for in paragraph (1) may be extended by the board for any of the following: (A) For good cause. (B) For time spent in a postgraduate training program, including, but not limited to, residency training, clinical training, fellowship training, remedial or refresher training, or other training that is intended to maintain or improve medical skills. (C) For an applicant who is a physician and surgeon in another state or a Canadian province who is currently and actively practicing medicine in that state or province. (3) Upon expiration of the 10-year period plus any extension granted by the board under paragraph (2), the applicant shall pass the Special Purpose Examination of the Federation of State Medical Boards or a clinical competency written examination determined by the board to be equivalent.