26 U.S.C. § 6233 (INTERNAL REVENUE CODE)
§ 6233. Interest and penalties
(a) Interest and penalties determined from reviewed year
(1) In general
Except to the extent provided in section 6226(c), in the case of a partnership adjustment for a reviewed year—
(A) interest shall be computed under paragraph (2), and
(B) the partnership shall be liable for any penalty, addition to tax, or additional amount as provided in paragraph (3).
(2) Determination of amount of interest
The interest computed under this paragraph with respect to any partnership adjustment is the interest which would be determined under chapter 67 for the period beginning on the day after the return due date for the reviewed year and ending on the return due date for the adjustment year (or, if earlier, the date payment of the imputed underpayment is made). Proper adjustments in the amount determined under the preceding sentence shall be made for adjustments required for partnership taxable years after the reviewed year and before the adjustment year by reason of such partnership adjustment.
(3) Penalties
Any penalty, addition to tax, or additional amount shall be determined at the partnership level as if such partnership had been an individual subject to tax under chapter 1 for the reviewed year and the imputed underpayment were an actual underpayment (or understatement) for such year.
(b) Interest and penalties with respect to adjustment year return
(1) In general
In the case of any failure to pay an imputed underpayment on the date prescribed therefor, the partnership shall be liable—
(A) for interest as determined under paragraph (2), and
(B) for any penalty, addition to tax, or additional amount as determined under paragraph (3).
(2) Interest
Interest determined under this paragraph is the interest that would be determined by treating the imputed underpayment as an underpayment of tax imposed in the adjustment year.
(3) Penalties
Penalties, additions to tax, or additional amounts determined under this paragraph are the penalties, additions to tax, or additional amounts that would be determined—
(A) by applying section 6651(a)(2) to such failure to pay, and
(B) by treating the imputed underpayment as an underpayment of tax for purposes of part II of subchapter A of chapter 68.
(c) Deposit to suspend interest
For rules allowing deposits to suspend running of interest on potential underpayments, see section 6603.
(Added Pub. L. 114–74, title XI, § 1101(c)(1), Nov. 2, 2015, 129 Stat. 633; amended Pub. L. 115–141, div. U, title II, § 206(i), Mar. 23, 2018, 132 Stat. 1180.)
heading: Prior Provisions
text: A prior section 6233, added Pub. L. 98–369, div. A, title VII, § 714(p)(1), July 18, 1984, 98 Stat. 964; amended Pub. L. 104–188, title I, § 1307(c)(3)(B), Aug. 20, 1996, 110 Stat. 1782, related to extension to entities filing partnership returns, prior to repeal by Pub. L. 114–74, title XI, § 1101(a), Nov. 2, 2015, 129 Stat. 625.
heading: Amendments
text: 2018—Subsec. (c). Pub. L. 115–141 added subsec. (c).
heading: Effective Date of 2018 Amendment
text: Amendment by Pub. L. 115–141 effective as if included in section 1101 of Pub. L. 114–74, see section 207 of Pub. L. 115–141, set out as a note under section 6031 of this title.
heading: Effective Date
text: Section applicable to returns filed for partnership taxable years beginning after Dec. 31, 2017, with certain exceptions, see section 1101(g) of Pub. L. 114–74, set out as a note under section 6221 of this title.