California Code, Public Contract Code - PCC § 10411

(a) No retired, dismissed, separated, or formerly employed person of any state agency or department employed under the state civil service or otherwise appointed to serve in state government may enter into a contract in which he or she engaged in any of the negotiations, transactions, planning, arrangements, or any part of the decisionmaking process relevant to the contract while employed in any capacity by any state agency or department.  The prohibition of this subdivision shall apply to a person only during the two-year period beginning on the date the person left state employment.

(b) For a period of 12 months following the date of his or her retirement, dismissal, or separation from state service, no person employed under state civil service or otherwise appointed to serve in state government may enter into a contract with any state agency, if he or she was employed by that state agency in a policymaking position in the same general subject area as the proposed contract within the 12-month period prior to his or her retirement, dismissal, or separation.  The prohibition of this subdivision shall not apply to a contract requiring the person's services as an expert witness in a civil case or to a contract for the continuation of an attorney's services on a matter with which he or she was involved prior to leaving state service.