; and (B) may not enroll in any other health benefits plan offered under any other section of this chapter. (2) Annuitants (A) Application A Postal Service annuitant shall not be subject to the requirements of this section if the Postal Service annuitant— (i) is enrolled in a health benefits plan under this chapter for the contract year immediately preceding the initial contract year that is not a health benefits plan offered by an initial participating carrier, unless— (I) the Postal Service annuitant voluntarily enrolls in a Program plan; (II) the health benefits plan in which such annuitant is enrolled for such contract year ceases to be available; or (III) the health benefits plan in which such annuitant is enrolled for such contract year becomes available as a Program plan; or (ii) resides in a geographic area for which there is not a Program plan in which the Postal Service annuitant may enroll. (B) Changed enrollment If a Postal Service annuitant changes enrollment to a health benefits plan under this chapter provided by a different carrier than the health benefits plan in which such annuitant is enrolled during the previous contract year, the Postal Service annuitant may only enroll in a Program plan. (3) Employees A Postal Service employee who is enrolled in a health benefits plan under this chapter for the contract year immediately preceding the initial contract year that is not a health benefits plan offered by an initial participating carrier shall not be subject to the requirements of this section, except that— (A) if the Postal Service employee changes enrollment to a different health benefits plan under this chapter during the open season for the initial contract year, or after the start of the initial contract year, the Postal Service employee may only enroll in a Program plan; (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