Notwithstanding any other provision of law: (a)

(1) The Board of Supervisors of Contra Costa County may, pursuant to a memorandum of understanding in accordance with the Meyers-Milias-Brown Act (Chapter 10 (commencing with

Section 3500) of Division of Title 1), adopt a resolution making this

section applicable to the officers and employees of the county specified in the resolution and specifying the future operative date of its application.

(2) After the board of supervisors has adopted that resolution, the governing body of a district may make this

section applicable to its officers and employees by adopting a resolution specifying the future operative date of its application, which date may not be earlier than the operative date of the resolution described in paragraph (1). (b)

(1) Except as otherwise provided in this section, Tier Three, as described in

Section 31755, shall apply to all officers and employees who become members or return to membership in the county or district, and with respect to service performed, on or after the date this

section becomes applicable in the county or district.

(2) On the date this

section becomes applicable in the county or district, those officers and employees specified in the resolution described in subdivision (

a) and then-subject to Tier Two shall thereafter be covered by Tier Three, as described in

Section 31755, for service performed on and after that date. (

c) This

section may not apply to an employee for any service performed while he or she is a safety member under this

chapter or is subject to Tier One, as described in

Section 31755. (

d) The benefit formula set forth in

Section shall apply to the Tier Two service with which a member is entitled to be credited at retirement. (

e) If the county adopts a resolution pursuant to subdivision (a), this

section shall apply equally to any nonrepresented employees in similar job classifications as employees within applicable bargaining units and to the supervisors and managers of those employees.