In this subchapter:
(1) “Employee” includes an officer of a political subdivision.
(2) “Employment” means service performed by an employee of a political subdivision except service:
(A) that in the absence of an agreement under this subchapter would constitute employment under the Social Security Act;
(B) that under the Social Security Act may not be included in an agreement between the retirement system and the secretary; or
(C) as a police officer in a position that, at the time the agreement is made, is subject to another retirement system of a municipality with a population of 250,000 or more, according to the most recent federal census before the date of the agreement.
(3) “Wages” means all remuneration for employment, including the cash value of all remuneration paid other than by cash. The term does not include remuneration that does not constitute “wages” under the Federal Insurance Contributions Act.