19-1-503. Required provisions of plan and agreement. A plan and agreement may not be approved by the department unless:

(1) they are in conformity with the requirements of the Social Security Act and with the agreement entered into under 19-1-401 and 19-1-402;

(2) they provide that all services that constitute employment and that are performed by employees of the political subdivisions will be covered by the plan and agreement, except that the plan and agreement may exclude services performed by individuals to whom section 218(c)(3)(B) of the Social Security Act, 42 U.S.C. 418(c)(3)(B), is applicable.