1. Each political subdivision of the state and each instrumentality of the state or of a political subdivision may submit for approval by the state agency a plan for extending the benefits of Title 2 of the Social Security Act (42 U.S.C.A. Section 401 et seq.) to its employees, and are hereby authorized to, by proper ordinance or resolution, enter into and ratify any such agreement upon its approval as aforesaid. Two or more political subdivisions or instrumentalities may form a joint plan if, in the absence of such joint plan, because of the requirements of the agreement entered into pursuant to section 105.310, or because of any requirement imposed by federal law, any subdivision included in such unit would be unable to submit an approvable plan.

2. Each plan or any amendment thereof shall be approved by the state agency if it finds that such plan is in conformity with the requirements provided by the regulations of the state agency, except that no plan shall be approved unless:

(1) It is in conformity with the requirements of the applicable federal law and with the agreement entered into under section 105.310;

(2) It provides that all services which constitute employment as defined in section 105.300 and are performed in the employ of the political subdivision or instrumentality, or in the employ of any member of a joint coverage unit are covered by the plan;

(3) It specifies the source or sources from which the funds necessary to make the payments required by section 105.370 are to be derived and contains reasonable assurance that such sources will be adequate for such purpose;

(4) It provides for methods of administration of the plan by the political subdivision or instrumentality or members of the joint coverage unit as are found by the state agency to be necessary for the proper and efficient administration of the plan.