California Code, Business and Professions Code - BPC § 2096

(a) In addition to other requirements of this chapter, before a physician's and surgeon's license may be issued, each applicant, including an applicant applying pursuant to Article 5 (commencing with Section 2105), shall show by evidence satisfactory to the board that the applicant has received credit for at least 12 months of board-approved postgraduate training for graduates of medical schools in the United States and Canada or 24 months of board-approved postgraduate training for graduates of foreign medical schools approved by the board pursuant to Section 2084 other than Canadian medical schools, pursuant to the attestation of the program director, designated institutional official, or delegated authority for the approved postgraduate training program where the applicant participated.

(b) The postgraduate training required by this section shall be obtained in a postgraduate training program approved by the Accreditation Council for Graduate Medical Education (ACGME) in the United States, the Royal College of Physicians and Surgeons of Canada (RCPSC) in Canada, or the College of Family Physicians of Canada (CFPC) in Canada.