The Secretary of Defense may prescribe by regulation a premium, deductible, copayment, or other charge for health care provided under this section. In the case of contracts for health care services under this section or health care plans offered under
section 1099 of this title for which the Secretary permits covered beneficiaries who are covered by
section 1086 of this title and who participate in such contracts or plans to pay an enrollment fee in lieu of meeting the applicable deductible amount specified in
section 1086(b) of this title, the Secretary may establish the same (or a lower) enrollment fee for covered beneficiaries described in
section 1086(d)(1) of this title who also participate in such contracts or plans. Without imposing additional costs on covered beneficiaries who participate in contracts for health care services under this section or health care plans offered under
section 1099 of this title, the Secretary shall permit such covered beneficiaries to pay, on a quarterly basis, any enrollment fee required for such participation. Except as provided by paragraph (2), a premium, deductible, copayment, or other charge prescribed by the Secretary under this subsection may not be increased during the period beginning on
April 1, 2006, and ending on
September 30, 2011.