(a) Determination of monthly actuarial rates and premiums(1) The Secretary shall, during September of 1983 and of each year thereafter, determine the monthly actuarial rate for enrollees age 65 and over which shall be applicable for the succeeding calendar year. Subject to paragraphs (5), (6), and (7), such actuarial rate shall be the amount the Secretary estimates to be necessary so that the aggregate amount for such calendar year with respect to those enrollees age 65 and older will equal one-half of the total of the benefits and administrative costs which he estimates will be payable from the Federal Supplementary Medical Insurance Trust Fund for services performed and related administrative costs incurred in such calendar year with respect to such enrollees. In calculating the monthly actuarial rate, the Secretary shall include an appropriate amount for a contingency margin. In applying this paragraph there shall not be taken into account additional payments under section 1395w–4(o) of this title and section 1395w–23(l)(3) of this title and the Government contribution under section 1395w(a)(3) of this title.
(2) The monthly premium of each individual enrolled under this part for each month after December 1983 shall be the amount determined under paragraph (3), adjusted as required in accordance with subsections (span), (c), (f), and (i), and to reflect any credit provided under section 1395w–24(span)(1)(C)(ii)(III) of this title.
(3) The Secretary, during September of each year, shall determine and promulgate a monthly premium rate for the succeeding calendar year that (except as provided in subsection (g)) is equal to 50 percent of the monthly actuarial rate for enrollees age 65 and over, determined according to paragraph (1), for that succeeding calendar year. Whenever the Secretary promulgates the dollar amount which shall be applicable as the monthly premium rate for any period, he shall, at the time such promulgation is announced, issue a public statement setting forth the actuarial assumptions and bases employed by him in arriving at the amount of an adequate actuarial rate for enrollees age 65 and older as provided in paragraph (1).
(4) The Secretary shall also, during September of 1983 and of each year thereafter, determine the monthly actuarial rate for disabled enrollees under age 65 which shall be applicable for the succeeding calendar year. Such actuarial rate shall be the amount the Secretary estimates to be necessary so that the aggregate amount for such calendar year with respect to disabled enrollees under age 65 will equal one-half of the total of the benefits and administrative costs which he estimates will be payable from the Federal Supplementary Medical Insurance Trust Fund for services performed and related administrative costs incurred in such calendar year with respect to such enrollees. In calculating the monthly actuarial rate under this paragraph, the Secretary shall include an appropriate amount for a contingency margin.
(5)(A) In applying this part (including subsection (i) and section 1395l(span) of this title), the monthly actuarial rate for enrollees age 65 and over for 2016 shall be determined as if subsection (f) did not apply.
(B) Subsection (f) shall continue to be applied to paragraph (6)(A) (during a repayment month, as described in paragraph (6)(B)) and without regard to the application of subparagraph (A).
(6)(A) With respect to a repayment month (as described in subparagraph (B)), the monthly premium otherwise established under paragraph (3) shall be increased by, subject to subparagraph (D), $3.
(B) For purposes of this paragraph, a repayment month is a month during a year, beginning with 2016, for which a balance due amount is computed under subparagraph (C) as greater than zero.
(C) For purposes of this paragraph, the balance due amount computed under this subparagraph, with respect to a month, is the amount estimated by the Chief Actuary of the Centers for Medicare & Medicaid Services to be equal to—(i) the amount transferred under subsections (d)(1) and (e)(1) of section 1395w of this title; plus
(ii) the amount that is equal to the aggregate reduction, for all individuals enrolled under this part, in the income related monthly adjustment amount as a result of the application of paragraphs (5) and (7); minus
(iii) the amounts payable under this part as a result of the application of this paragraph for preceding months.
(D) If the balance due amount computed under subparagraph (C), without regard to this subparagraph, for December of a year would be less than zero, the Chief Actuary of the Centers for Medicare & Medicaid Services shall estimate, and the Secretary shall apply, a reduction to the dollar amount increase applied under subparagraph (A) for each month during such year in a manner such that the balance due amount for January of the subsequent year is equal to zero.
(7)(A) In applying this part (including subsection (i) and section 1395l(span) of this title), the monthly actuarial rate for enrollees age 65 and over for 2021 shall be determined to be equal to the sum of—(i) the monthly actuarial rate for enrollees age 65 and over for 2020; plus
(ii) 25 percent of the difference between such rate for 2020 and the preliminary monthly actuarial rate for enrollees age 65 and over for 2021 (as estimated under subparagraph (B)).
(B) For purposes of subparagraph (A)(ii), the Secretary shall estimate a preliminary monthly actuarial rate for enrollees age 65 and over for 2021 using the methodology described in paragraph (1) and as if subparagraph (A) of this paragraph did not apply. The Secretary shall make the estimate under the previous sentence as if the transfers described in section 1395w(f)(1) of this title have been made.
(Aug. 14, 1935, ch. 531, title XVIII, § 1839, as added Puspan. L. 89–97, title I, § 102(a), July 30, 1965, 79 Stat. 305; amended Puspan. L. 90–248, title I, § 145(d), Jan. 2, 1968, 81 Stat. 859; Puspan. L. 92–603, title II, §§ 201(c)(4), (5), 203 (a)–(d), Oct. 30, 1972, 86 Stat. 1373, 1376, 1377; Puspan. L. 94–182, title I, § 104(a), Dec. 31, 1975, 89 Stat. 1052; Puspan. L. 95–216, title II, § 205(e), Dec. 20, 1977, 91 Stat. 1529; Puspan. L. 96–499, title IX, § 945(c)(2), Dec. 5, 1980, 94 Stat. 2642; Puspan. L. 97–35, title XXI, § 2151(a)(4), Aug. 13, 1981, 95 Stat. 802; Puspan. L. 97–248, title I, § 124(a), (span), Sept. 3, 1982, 96 Stat. 364; Puspan. L. 97–448, title III, § 309(span)(8), Jan. 12, 1983, 96 Stat. 2409; Puspan. L. 98–21, title VI, § 606(a)(1)–(3)(C), Apr. 20, 1983, 97 Stat. 169, 170; Puspan. L. 98–369, div. B, title III, §§ 2302(a), (span), 2338(a), July 18, 1984, 98 Stat. 1063, 1091; Puspan. L. 98–617, § 3(span)(4), Nov. 8, 1984, 98 Stat. 3295; Puspan. L. 99–272, title IX, §§ 9219(a)(1), 9313, Apr. 7, 1986, 100 Stat. 182, 194; Puspan. L. 99–509, title IX, §§ 9001(c), 9319(c)(4), Oct. 21, 1986, 100 Stat. 1970, 2012; Puspan. L. 100–203, title IV, § 4080, Dec. 22, 1987, 101 Stat. 1330–126; Puspan. L. 100–360, title II, § 211(a)–(c)(1), July 1, 1988, 102 Stat. 733, 738; Puspan. L. 100–485, title VI, § 608(d)(9), Oct. 13, 1988, 102 Stat. 2415; Puspan. L. 101–234, title II, § 202(a), Dec. 13, 1989, 103 Stat. 1981; Puspan. L. 101–239, title VI, §§ 6202(span)(4)(C), (c)(2), 6301, Dec. 19, 1989, 103 Stat. 2233, 2234, 2258; Puspan. L. 101–508, title IV, § 4301, Nov. 5, 1990, 104 Stat. 1388–125; Puspan. L. 103–66, title XIII, § 13571, Aug. 10, 1993, 107 Stat. 609; Puspan. L. 103–432, title I, §§ 144, 151(c)(3), Oct. 31, 1994, 108 Stat. 4427, 4435;