26 C.F.R. § 1.264-3
Pursuant to section 7851(a)(1)(C), the regulations prescribed in § 1.264-2 , to the extent that they relate to amounts paid or accrued on indebtedness incurred or continued to purchase or carry a single premium annuity contract purchased after March 1, 1954, and to the extent they consider a contract a single premium life insurance, endowment, or annuity contract if an amount is deposited after March 1, 1954, with the insurer for payment of a substantial number of future premiums on the contract, shall also apply to taxable years beginning before January 1, 1954, and ending after March 1, 1954, and to taxable years beginning after December 31, 1953, and ending after March 1, 1954, but before August 17, 1954, although such years are subject to the Internal Revenue Code of 1939.
26 C.F.R. §1.264-3