; (B) if the health benefits plan in which such employee is enrolled for such contract year becomes available as a Program plan, the Postal Service employee may only enroll in a Program plan; (C) upon becoming a Postal Service annuitant, if the Postal Service employee elects to continue coverage under this chapter, the Postal Service employee shall enroll in a Program plan during the open season that is— (i) being held when the Postal Service employee becomes a Postal Service annuitant; or (ii) if the date on which the Postal Service employee becomes a Postal Service annuitant falls outside of an open season, the first open season following that date; and (D) subparagraphs (A), (B), and (C) shall not apply to an employee who resides in a geographic area for which there is not a Program plan in which the employee may enroll. (e) Requirement of Medicare enrollment for annuitants and their family members (1) Postal service medicare covered annuitants A Postal Service Medicare covered annuitant subject to the requirements of this section may not obtain coverage under this chapter unless the annuitant is enrolled in part B of title XVIII of the Social Security Act ( 42 U.S.C. 1395j et seq.). (2) Medicare covered family members If a family member of a Postal Service annuitant who is subject to the requirements of this section is a covered Medicare individual, the family member may not be covered under the Program as a family member of the Postal Service annuitant unless the family member is enrolled in part B of title XVIII of the Social Security Act ( 42 U.S.C. 1395j et seq.). (3) Process for coordinated election of enrollment under Medicare part B The Office shall establish a process under which— (A) Postal Service annuitants and family members who are subject to the requirements of paragraph (1) or (2)— (i) are informed, at the time of enrollment under this chapter, of such requirement; (ii) receive requests for any additional information necessary for enrollment in writing