TITLE 26. INTERNAL REVENUE CODE § 6654. Failure by individual to pay estimated income tax., 26 USCS § 6654

Summary

(a) Addition to the tax. Except as otherwise provided in this section, in the case of any underpayment of estimated tax by an individual, there shall be added to the tax under chapter 1 [26 USCS §§ 1 et seq.], the tax under chapter 2 [26 USCS §§ 1401 et seq.], and the tax under chapter 2A [26 USCS §§ 1411] for the taxable year an amount determined by applying—

(1) the underpayment rate established under section 6621 [26 USCS § 6621],

(2) to the amount of the underpayment,

(3) for the period of the underpayment.

(b) Amount of underpayment; period of underpayment. For purposes of subsection (a)

(1) Amount. The amount of the underpayment shall be the excess of—

(A) the required installment, over

(B) the amount (if any) of the installment paid on or before the due date for the installment.

(2) Period of underpayment. The period of the underpayment shall run from the due date for the installment to whichever of the following dates is the earlier—

(A) the 15th day of the 4th month following the close of the ...