Insurance heretofore granted under the provisions of section 621 of the National Service Life Insurance Act of 1940, against the death of the policyholder occurring while such insurance is in force, is subject to the same terms and conditions as are contained in standard policies of National Service Life Insurance on the five-year level premium term plan except (1) such insurance may not be exchanged for or converted to insurance on any other plan; (2) the premium rates for such insurance shall be based on the Commissioners 1941 Standard Ordinary Table of Mortality and interest at the rate of 2¼ per centum per annum; (3) all settlements on policies involving annuities shall be calculated on the basis of The Annuity Table for 1949, and interest at the rate of 2¼ per centum per annum; (4) all premiums and other collections on such insurance and any total disability provisions added thereto shall be credited to a revolving fund in the Treasury of the United States, which, together with interest earned thereon, shall be available for the payment of liabilities under such insurance and any total disability provisions added thereto, including payments of dividends and refunds of unearned premiums, and for the reimbursement of administrative costs under subsection (d).

Any term insurance heretofore issued under section 621 of the National Service Life Insurance Act of 1940, may be converted to a permanent plan of insurance or exchanged for a policy of limited convertible five-year level premium term insurance issued under this subsection. Insurance issued under this subsection shall be issued upon the same terms and conditions as are contained in the standard policies of National Service Life Insurance except (1) after September 1, 1960, limited convertible term insurance may not be issued or renewed on the term plan after the insured’s fiftieth birthday; (2) the premium rates for such limited convertible term or permanent plan insurance shall be based on table X–18 (1950–54 Intercompany Table of Mortality) and interest at the rate of 2½ per centum per annum; (3) all settlements on policies involving annuities on insurance issued under this subsection shall be calculated on the basis of The Annuity Table for 1949, and interest at the rate of 2½ per centum per annum; (4) all cash, loan, paid-up, and extended values, and, except as otherwise provided in this subsection, all other calculations in connection with insurance issued under this subsection shall be based on table X–18 (1950–54 Intercompany Table of Mortality) and interest at the rate of 2½ per centum per annum; (5) all premiums and other collections on insurance issued under this subsection and any total disability income provisions added thereto shall be credited directly to the revolving fund referred to in subsection (a) of this section, which together with interest earned thereon, shall be available for the payment of liabilities under such insurance and any total disability provisions added thereto, including payments of dividends and refunds of unearned premiums.

The Secretary is authorized to invest in, and the Secretary of the Treasury is authorized to sell and retire, special interest-bearing obligations of the United States for the account of the revolving fund with a maturity date as may be agreed upon by the two Secretaries. The rate of interest on such obligations shall be fixed by the Secretary of the Treasury at a rate equal to the rate of interest, computed as of the end of the month preceding the date of issue of such obligations, borne by all marketable interest-bearing obligations of the United States then forming a part of the public debt that are not due or callable until after the expiration of five years from the date of original issue; except that where such average rate is not a multiple of one-eighth of 1 per centum, the rate of interest of such obligations shall be the multiple of one-eighth of 1 per centum nearest such average rate.