California Code, Business and Professions Code - BPC § 6762.5

(a) The board shall issue, upon application and payment of the fee established by Section 6799, a retired license (registration), to an engineer who has been licensed by the board for a minimum of 5 years within California and a minimum of 20 years within the United States or territory of the United States, and who holds a license that is not suspended, revoked, or otherwise disciplined, or subject to pending discipline under this chapter.

(b) The holder of a retired license issued pursuant to this section shall not engage in any activity for which an active engineer's license is required.  An engineer holding a retired license shall be permitted to use the titles “retired professional engineer,” “professional engineer, retired,” or either of those titles with the licensee's branch designation inserted for the word “professional” for example, “retired civil engineer” or “civil engineer, retired.”

(c) The holder of a retired license shall not be required to renew that license.

(d) In order for the holder of a retired license issued pursuant to this section to restore his or her license to active status, he or she shall pass the second division examination that is required for initial licensure with the board.