Cal. Government Code § 31663.15

(a) Sections 31662.4, 31662.6, 31662.8, and 31663 shall not apply to a person who is an active safety member described in Section 31469.3 or 31470.4 if a physician employed or approved by the county certifies that the safety member is capable of performing his or her assigned duties pursuant to standards set forth by the member’s employer. (b) This section shall also apply to a member who reinstates from retirement pursuant to Section 31680.8. (c) A county that adopts this section shall provide a safety member who is on a disability leave of absence the opportunity to receive the physician certification described in subdivision (a) upon return from his or her leave, and that member shall not be subject to mandatory retirement pursuant to Section 31662.4, 31662.6, or 31662.8 prior to receiving that opportunity. (d) This section applies only to a county of the first class, as defined by Section 28020, as amended by Chapter 1204 of the Statutes of 1971, and Section 28022, as amended by Chapter 43 of the Statutes of 1961. (e) This section shall not be operative in any county until the board of supervisors shall, by resolution adopted by a majority vote, make this section and Section 31680.8 applicable in the county. The resolution of the board of supervisors may designate a date, which may be prior to the date of the resolution or the effective date of this section, upon which the resolution and this section shall be operative in the county, and may further provide that a member, described in Section 31470.4, who retired pursuant to Section 31662.4 or 31662.6, prior to April 1, 2007, is not eligible to reinstate from retirement pursuant to Section 31680.8.