Cal. EDC § 24111

(a) A member who is receiving a disability retirement allowance under this part pursuant to this chapter who is determined by the board to have a mental, physical, or vocational rehabilitation potential that could be expected to restore the member’s ability to perform service in the member’s former position of employment or in a comparable level position shall participate in an appropriate rehabilitation program approved by the board. The board shall pay all reasonable costs of the approved program. Willful failure to initiate and continue participation in the rehabilitation program shall cause the disability retirement allowance under this part to be terminated. In determining whether a member has good cause for failure to participate in the program, the board shall take into account whether the participation would abridge the member’s right to the free exercise of religion or whether the member’s physical or mental condition has worsened as determined by the member’s treating physician and substantiated by medical evidence.

(b) Any cost for the approved rehabilitation program prescribed by the board shall be paid directly by the system from the fund.