California Code, Vehicle Code - VEH § 12502

(1) A nonresident over the age of 18 years having in his or her immediate possession a valid driver's license issued by a foreign jurisdiction of which he or she is a resident, except as provided in Section 12505.

(2) A nonresident, 21 years of age or older, if transporting hazardous material, as defined in Section 353, in a commercial vehicle, having in his or her immediate possession, a valid license with the appropriate endorsement issued by another state or other jurisdiction that is recognized by the department, or a Canadian driver's license and a copy of his or her current training certificate to transport hazardous material that complies with all federal laws and regulations with respect to hazardous materials, both of which shall be in his or her immediate possession.

(3) A nonresident having in his or her immediate possession a valid driver's license, issued by the Diplomatic Motor Vehicle Office of the Office of Foreign Missions of the United States Department of State, for the type of motor vehicle or combination of vehicles that the person is operating.

(b)(1) A driver required to have a commercial driver's license under Part 383 of Title 49 of the Code of Federal Regulations who submits a current medical examiner's certificate to the licensing state in accordance with Section 383.71(h) of Subpart E of Part 383 of Title 49 of the Code of Federal Regulations, documenting that he or she meets the physical qualification requirements of Section 391.41 of Subpart E of Part 391 of Title 49 of the Code of Federal Regulations, is not required to carry on his or her person the medical examiner's certificate or a copy of that certificate.

(2) A driver may use the date-stamped receipt, given to the driver by the licensing state agency, for up to 15 days after the date stamped on the receipt, as proof of medical certification.