(a) Old-age, survivors, and disability insurance In addition to other taxes, there is hereby imposed on every employer an excise tax, with respect to having individuals in his employ, equal to the following percentages of the wages (as defined in section
3121 (a)) paid by him with respect to employment (as defined in section
3121 (b))
(b) Hospital insurance In addition to the tax imposed by the preceding subsection, there is hereby imposed on every employer an excise tax, with respect to having individuals in his employ, equal to the following percentages of the wages (as defined in section
3121 (a)) paid by him with respect to employment (as defined in section
3121 (b))
(1) with respect to wages paid during the calendar years 1974 through 1977, the rate shall be 0.90 percent;
(2) with respect to wages paid during the calendar year 1978, the rate shall be 1.00 percent;
(3) with respect to wages paid during the calendar years 1979 and 1980, the rate shall be 1.05 percent;
(4) with respect to wages paid during the calendar years 1981 through 1984, the rate shall be 1.30 percent;
(5) with respect to wages paid during the calendar year 1985, the rate shall be 1.35 percent; and
(6) with respect to wages paid after December 31, 1985, the rate shall be 1.45 percent.