Pub. L. 87-408, tit. III, sec. 319
Elimination of Fractional Stamps or Devices.—
Sec. 319. Elimination of Fractional Stamps or Devices.— For the purpose of avoiding, in the case of any stamps or devices employed pursuant to authority of this title, the issuance of stamps or the employment of devices representing fractional parts of $1, the Commissioners are authorized, in their discretion, to limit the denominations of such stamps or devices to amounts representing $1 or multiples of $1, and to prescribe further that where part of the tax due is a fraction of $1, the tax paid shall be paid to the nearest dollar.