(a)
A county superintendent of schools, a school district, a community college district, or a contracting agency, whose respective resolution or contract contains an election to be subject to this section, may offer to its part-time employees whose service is less than the minimum service prescribed by paragraph (2) of subdivision (a) of Section 20305 the option to elect at any time to become a member by filing an election in writing with the board to become a member. An election by a county superintendent of schools, a school district, or a community college district to be subject to this section shall subject all of its employees whose service is less than the minimum service prescribed by paragraph (2) of subdivision (a) of Section 20305 to mandatory social security coverage but shall not, in and of itself, affect any other county superintendent of schools, school district, or community college district with respect to any social security coverage of employees of the other county superintendent of schools, school district, or community college district.
(b)
If a part-time employee elects to become a member, he or she may further elect at any time prior to retirement to receive service credit for past service that was less than the minimum service prescribed by paragraph (2) of subdivision (a) of Section 20305 by making the contributions as specified in Sections 21050 and 21051.
(c)
This section shall not apply to those part-time employees of any contracting agency nor to any contracting agency until the contracting agency elects to be subject to this section by amendment to its contract with the board made pursuant to Section 20474 or by express provision in its contract with the board.
(d)
This section shall not apply to those part-time employees of any county superintendent of schools or school district or community college district nor to any county superintendent of schools or school district or community college district until the county superintendent of schools, the school district, or community college district, elects to be subject to this section by adopting a resolution to that effect and transmitting that resolution through the county superintendent of schools to the board. Notwithstanding any specified effective date in a resolution, the resolution shall not become effective until it is received by this system.