Ind. Code § 5-10.1-2-7
Termination of Coverage. Coverage by the Social Security Act may be terminated by sending a written notice of termination to the federal administrator. The termination is effective if:
(2) the employees have been covered for five (5) years or more before the date on which the federal administrator receives the notice.
As added by Acts 1977, P.L.53, SEC.1.