((a)) There shall be paid from the Fund amounts payable for the costs of all uniformed service retiree health care programs for the benefit of members or former members of a participating uniformed service who are entitled to retired or retainer pay and are medicare eligible, and eligible dependents who are medicare eligible.

((b)) The assets of the Fund are hereby made available for payments under subsection (a).

((c))

((1)) In carrying out subsection (a), the Secretary of Defense may transfer periodically from the Fund to applicable appropriations of the Department of Defense, or to applicable appropriations of other departments or agencies, such amounts as the Secretary determines necessary to cover the costs chargeable to those appropriations for uniformed service retiree health care programs for beneficiaries under those programs who are medicare-eligible. Such transfers may include amounts necessary for the administration of such programs. Amounts so transferred shall be merged with and be available for the same purposes and for the same time period as the appropriation to which transferred. Upon a determination that all or part of the funds transferred from the Fund are not necessary for the purposes for which transferred, such amounts may be transferred back to the Fund. This transfer authority is in addition to any other transfer authority that may be available to the Secretary.

((2)) A transfer from the Fund under paragraph (1) may not be made to an appropriation after the end of the second fiscal year after the fiscal year that the appropriation is available for obligation. A transfer back to the Fund under paragraph (1) may not be made after the end of the second fiscal year after the fiscal year for which the appropriation to which the funds were originally transferred is available for obligation.

((d)) The Secretary of Defense shall by regulation establish the method or methods for calculating amounts to be transferred under subsection (c). Such method or methods may be based (in whole or in part) on a proportionate share of the volume (measured as the Secretary determines appropriate) of health care services provided or paid for under uniformed service retiree health care programs for beneficiaries under those programs who are medicare-eligible in relation to the total volume of health care services provided or paid for under Department of Defense health care programs.

((e)) The regulations prescribed by the Secretary under subsection (d) shall be provided to the Comptroller General not less than 60 days before such regulations become effective. The Comptroller General shall, not later than 30 days after receiving such regulations, report to the Secretary of Defense and Congress on the adequacy and appropriateness of the regulations.

((f)) If the Secretary of Defense enters into an agreement with another administering Secretary pursuant to section 1111(c), the Secretary of Defense may take the actions described in subsections (c), (d), and (e) on behalf of the beneficiaries and programs of the other participating uniformed service.