; and (2) provide such additional elements of coverage as the Secretary shall prescribe for purposes of this subchapter. 2604. Health insurance support (a) In general The Secretary shall provide health insurance support to veterans eligible for such support under this subchapter through premium support under subsections (b) and (c), cost-sharing support under subsection (d), and alternative support under subsection (e) by paying or reimbursing such veterans for the costs associated with such health insurance support. The Secretary shall make such payments or reimbursements in a manner similar to the manner in which the Centers for Medicare & Medicaid Services make similar payments and reimbursements. (b) Premium support generally The premium support provided by the Secretary under this subsection is as follows: (1) Tier 1 To any veteran with a service-connected disability rated as 100 percent disabling, health insurance support sufficient to provide benefits to the veteran under a health plan that are actuarially equivalent to 100 percent of the full actuarial value of the benefits provided under the health plan. A health plan under this paragraph may be referred to as a Tier 1 Plan . (2) Tier 2 To any veteran in priority group 1 not covered by paragraph (1) and any veteran in priority group 2, health insurance support sufficient to provide benefits to the veteran under a health plan that are actuarially equivalent to 90 percent of the full actuarial value of the benefits provided under the health plan. A health plan under this paragraph may be referred to as a Tier 2 Plan . (3) Tier 3 To any veteran in priority group 3 or priority group 4, health insurance support sufficient to provide benefits to the veteran under a health plan that are actuarially equivalent to 80 percent of the full actuarial value of the benefits provided under the health plan. A health plan under this paragraph may be referred to as a Tier 3 Plan . (4) Tier 4 To any veteran in priority group 5 or priority group 6, health insurance support