the taxes imposed by subchapter E of chapter 1 of the Internal Revenue Code of 1939, with respect to self-employment income (as defined in section 481 of such Code), and by chapter 2 (other than section 1401(b)) of the Internal Revenue Code of 1954 with respect to self-employment income (as defined in section 1402 of such Code) reported to the Commissioner of Internal Revenue on tax returns under such subchapter or to the Secretary of the Treasury or his delegate on tax returns under subtitle F of such Code, as determined by the Secretary of the Treasury by applying the applicable rate of tax under such subchapter or chapter (other than section 1401(b)) to such self-employment income, which self-employment income shall be certified by the Commissioner of Social Security on the basis of the records of self-employment income established and maintained by the Commissioner of Social Security in accordance with such returns, less the amounts specified in clause (2) of subsection (b) of this section.
The amounts appropriated by clauses (3) and (4) of this subsection shall be transferred from time to time from the general fund in the Treasury to the Federal Old-Age and Survivors Insurance Trust Fund, and the amounts appropriated by clauses (1) and (2) of subsection (b) shall be transferred from time to time from the general fund in the Treasury to the Federal Disability Insurance Trust Fund, such amounts to be determined on the basis of estimates by the Secretary of the Treasury of the taxes, specified in clauses (3) and (4) of this subsection, paid to or deposited into the Treasury; and proper adjustments shall be made in amounts subsequently transferred to the extent prior estimates were in excess of or were less than the taxes specified in such clauses (3) and (4) of this subsection. All amounts transferred to either Trust Fund under the preceding sentence shall be invested by the Managing Trustee in the same manner and to the same extent as the other assets of such Trust Fund. Notwithstanding the preceding sentence, in any case in which the Secretary of the Treasury determines that the assets of either such Trust Fund would otherwise be inadequate to meet such Fund’s obligations for any month, the Secretary of the Treasury shall transfer to such Trust Fund on the first day of such month the amount which would have been transferred to such Fund under this section as in effect on October 1, 1990 ; and such Trust Fund shall pay interest to the general fund on the amount so transferred on the first day of any month at a rate (calculated on a daily basis, and applied against the difference between the amount so transferred on such first day and the amount which would have been transferred to the Trust Fund up to that day under the procedures in effect on January 1, 1983 ) equal to the rate earned by the investments of such Fund in the same month under subsection (d).
