(a) The state agency, with the approval of the Governor, is authorized to enter on behalf of the state into an agreement with the secretary of health and human services, consistent with the terms of this chapter, for the purpose of extending the benefits of the federal old-age, survivors, and disability insurance system to employees of the political subdivisions of this state and with respect to services specified in such agreement which constitute employment within the meaning of this chapter. Such agreement may contain such provisions relating to coverage, benefits, contributions, effective date, modification and termination of the agreement, administration, and other appropriate provisions as the state agency and the secretary of health and human services shall agree upon. Except as may be otherwise required by or under the Social Security Act as to the services to be covered, such agreement shall provide that:

(1) Benefits shall be provided for employees whose services are covered by the agreement, and their dependents and survivors, on the same basis as though such services constituted employment within the meaning of Title II of the Social Security Act;

(2) At such times as may be prescribed under the Social Security Act, the state shall pay contributions to the secretary of the treasury with respect to wages equal to the sum of the taxes which would be imposed by the Federal Insurance Contributions Act, if the services covered by the agreement constituted employment within the meaning of that Act;

(3) Such agreement shall be effective as of the date specified in the agreement, provided that it shall not be effective prior to the date permitted by the federal Social Security Act with respect to services in employment covered by the agreement;

(4) All services which (A) constitute employment, (B) are performed in the employ of the state or a political subdivision of the state, and (C) are covered by a plan which is in conformity with the terms of the agreement and has been approved by the state agency under Code Section 47-18-41 shall be covered by the agreement; and

(5) As modified, the agreement shall include all services described in paragraph (4) of this subsection and performed by individuals in positions covered by a retirement system with respect to which the Governor has issued a certificate to the secretary of health and human services, pursuant to subsection (b) of Code Section 47-18-42.

(b) Any instrumentality jointly created by this state and any other states is authorized, upon the granting of like authority by such other states:

(1) To enter into an agreement with the secretary of health and human services whereby the benefits of the federal old-age, survivors, and disability insurance system shall be extended to employees of such instrumentality;

(2) To require its employees to pay, and for that purpose to deduct from their wages, contributions equal to the amounts which they would be required to pay under subsection (a) of Code Section 47-18-41 if they were covered by an agreement made pursuant to subsection (a) of this Code section; and

(3) To make payments in accordance with federal law.

Such agreement, to the extent practicable, shall be consistent with the terms and provisions of subsection (a) of this Code section and other provisions of this chapter.

(c) Pursuant to Section 218(d)(6) of the Social Security Act and for purposes of this chapter, at the election of the Governor, any retirement system which covers employees of more than one political subdivision or employees of the state and one or more political subdivisions shall be deemed a separate retirement system with respect to each such political subdivision or as to the state and one or more political subdivisions with positions covered by such retirement system. Pursuant to Section 218(p) of the Social Security Act and also for the purposes of this chapter, any retirement system which covers positions of policemen or firemen, or both, and other positions shall, if the Governor so elects, be deemed to be a separate retirement system with respect to the positions of such policemen or firemen, or both, as the case may be.

(d) For the purposes of this chapter, any retirement system established by this state or any political subdivision thereof or established by an Act of the General Assembly which, on, before, or after March 21, 1958, is divided into two divisions or parts, one of which is composed of positions of members of such system who desire coverage under the agreement under this chapter and the other of which is composed of positions of members of such system who do not desire such coverage, shall, upon the Governor's authorization of a referendum for a retirement system pursuant to Section 218 of the Social Security Act, be deemed to be a separate retirement system with respect to each such division or part. At the election of the Governor, the referendum and the division of such system may occur simultaneously as authorized by Section 218(d)(7) of the Social Security Act. The positions of individuals who become members of such system after such coverage is extended shall be included in such division or part of such system composed of members desiring such coverage. The position of any individual which is covered by any such retirement system, if such individual is ineligible to become a member of such system on August 1, 1956, or, if later, the day he or she first occupies such position, shall be deemed to be covered by the separate retirement system consisting of the positions of members of the division or part who do not desire coverage under this chapter.