§ 4974. Excise tax on certain accumulations in qualified retirement plans
General rule If the amount distributed during the taxable year of the payee under any qualified retirement plan or any eligible deferred compensation plan (as defined in section
(b)) is less than the minimum required distribution for such taxable year, there is hereby imposed a tax equal to 50 percent of the amount by which such minimum required distribution exceeds the actual amount distributed during the taxable year. The tax imposed by this section shall be paid by the payee.