26 U.S.C. § 6313

Fractional parts of a cent

In the payment of any tax imposed by this title, a fractional part of a cent shall be disregarded unless it amounts to one-half cent or more, in which case it shall be increased to 1 cent.

( Aug. 16, 1954, ch. 736 , 68A Stat. 778 ; Pub. L. 94–455, title XIX, § 1906(a)(19) , Oct. 4, 1976 , 90 Stat. 1825 .)