45 CFR § 156.140 - Levels of coverage.
(a) General requirement for levels of coverage. AV, calculated as described in § 156.135 of this subpart, and within a de minimis variation as defined in paragraph (c) of this section, determines whether a health plan offers a bronze, silver, gold, or platinum level of coverage.
(b) The levels of coverage are:
(1) A bronze health plan is a health plan that has an AV of 60 percent.
(2) A silver health plan is a health plan that has an AV of 70 percent.
(3) A gold health plan is a health plan that has an AV of 80 percent.
(4) A platinum health plan is a health plan that has as an AV of 90 percent.
(c) De minimis variation. For plan years beginning on or after January 1, 2018, the allowable variation in the AV of a health plan that does not result in a material difference in the true dollar value of the health plan is −4 percentage points and +2 percentage points, except if a health plan under paragraph (b)(1) of this section (a bronze health plan) either covers and pays for at least one major service, other than preventive services, before the deductible or meets the requirements to be a high deductible health plan within the meaning of 26 U.S.C. 223(c)(2), in which case the allowable variation in AV for such plan is −4 percentage points and +5 percentage points.