; applicability (1) In general Subject to paragraph (2), this Act, and the amendments made by this Act, shall take effect on the first day of the first pay period commencing on or after the date of enactment of this Act. (2) Retroactive application (A) In general Any availability pay received for any pay period commencing before the date of enactment of this Act by a Federal air marshal or criminal investigator employed by the Transportation Security Administration shall be deemed basic pay under section 8331(3) of title 5, United States Code, if the Transportation Security Administration treated such pay as retirement-creditable basic pay, but the Office of Personnel Management, based on an interpretation of section 8331(3) of title 5, United States Code, did not accept such pay as retirement-creditable basic pay. (B) Implementation Not later than 3 months after the date of enactment of this Act, the Director of the Office of Personnel Management shall commence taking such actions as are necessary to implement the amendments made by this section with respect to availability pay deemed to be basic pay under subparagraph (A).