Cal. Lab. Code § 6201

The employer or insurance carrier shall notify the injured employee of the availability of rehabilitation services in those cases where there is continuing disability of 28 days and beyond. Notification shall be made at the time the employee is paid retroactively for the first day of disability (in cases of 28 days of continuing disability or hospitalization) which has previously been uncompensated. A copy of said notification shall be forwarded to the State Department of Rehabilitation.