; and (B) may only enroll in a PSHBP plan. (2) Annuitants A Postal Service annuitant shall not be subject to this section if the Postal Service annuitant— (A) is enrolled in a health benefits plan under this chapter for the contract year before the initial contract year that is not a health benefits plan offered by an initial participating carrier, unless the Postal Service annuitant voluntarily enrolls in a PSHBP plan; (B) resides in a geographic area— (i) for which there is not a PSHBP plan in which the Postal Service annuitant may enroll; or (ii) in which there is a lack of participating Medicare part B providers; or (C) would not derive benefit from enrolling in Medicare part B because of comprehensive medical coverage provided by the Department of Veterans Affairs or other programs. (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 under 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 PSHBP plan; (B) if the health benefits plan in which the Postal Service employee is enrolled for such contract year becomes available as a PSHBP plan, the Postal Service employee may only enroll in a PSHBP 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 PSHBP plan during— (i) the open season that is being held when the Postal Service employee becomes a Postal Service annuitant