California Code, Vehicle Code - VEH § 13556

(a) Unless otherwise specifically provided in this chapter, no suspension of a license by the department shall be for a longer period than six months, except that the department may suspend a license for a maximum period of 12 months in those cases when a discretionary revocation would otherwise be authorized pursuant to this chapter.

(b) Any discretionary suspension, the ending of which is dependent upon an action by the person suspended and which has been in effect for eight years, may be ended at the election of the department.

(c) Notwithstanding any other provisions of this code, a suspension based upon a physical or mental condition shall continue until evidence satisfactory to the department establishes that the cause for which the action was taken has been removed or no longer renders the person incapable of operating a motor vehicle safely.