; (2) the term initial participating carrier means a carrier that enters into a contract with the Office to participate in the Postal Service Health Benefits Program during the initial contract year; (3) the term Medicare eligible individual means an individual who— (A) is entitled to Medicare part A, but excluding an individual who is eligible to enroll under such part under section 1818 of the Social Security Act ( 42 U.S.C. 1395i–2 ); and (B) is eligible to enroll in Medicare part B; (4) the term Medicare part A means the Medicare program for hospital insurance benefits under part A of title XVIII of the Social Security Act ( 42 U.S.C. 1395c et seq.); (5) the term Medicare part B means the Medicare program for supplementary medical insurance benefits under part B of title XVIII of the Social Security Act ( 42 U.S.C. 1395j et seq.); (6) the term Medicare part D means the Medicare insurance program established under part D of title XVIII of the Social Security Act ( 42 U.S.C. 1395w–101 et seq.); (7) the term Office means the Office of Personnel Management; (8) the term Postal Service means the United States Postal Service; (9) the term Postal Service annuitant means an annuitant enrolled in a health benefits plan under this chapter whose Government contribution is paid by the Postal Service or the Postal Service Retiree Health Benefits Fund under section 8906(g)(2); (10) the term Postal Service employee means an employee of the Postal Service enrolled in a health benefits plan under this chapter; (11) the term Postal Service Health Benefits Program means the program of health benefits plans established under subsection (c) within the Federal Employees Health Benefits Program under this chapter; (12) the term Postal Service Medicare eligible annuitant means an individual who— (A) is a Postal Service annuitant; and (B) is a Medicare eligible individual; (13) the term PSHBP plan means a health benefits plan offered under the Postal Service Health Benefits Program