§ 6201.
(a)
Authority of Secretary
The Secretary is authorized and required to make the inquiries, determinations, and assessments of all taxes (including interest, additional amounts, additions to the tax, and assessable penalties) imposed by this title, or accruing under any former internal revenue law, which have not been duly paid by stamp at the time and in the manner provided by law. Such authority shall extend to and include the following:
(1)
Taxes shown on return
(2)
Unpaid taxes payable by stamp
(B)
Check or money order not duly paid
(3)
Erroneous income tax prepayment credits
(4)
Certain orders of criminal restitution
(C)
Restriction on challenge of assessment
([Aug. 16, 1954, ch. 736], [68A Stat. 767]; [Pub. L. 89–44, title VIII, § 809(d)(4)(A)], June 21, 1965, [79 Stat. 168]; [Pub. L. 91–53, § 2(b)], Aug. 7, 1969, [83 Stat. 92]; [Pub. L. 91–172, title I, § 101(j)(38)], Dec. 30, 1969, [83 Stat. 530]; [Pub. L. 91–258, title II, § 207(d)(1)], (2), May 21, 1970, [84 Stat. 248]; [Pub. L. 93–406, title II, § 1016(a)(8)], Sept. 2, 1974, [88 Stat. 929]; [Pub. L. 94–12, title II, § 204(b)(2)]