### §6654. Failure by individual to pay estimated income tax

#### (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, the tax under chapter 2, and the tax under chapter 2A for the taxable year an amount determined by applying—

(1) the underpayment rate established under section 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 taxable year, or

(B) with respect to any portion of the underpayment, the date on which such portion is paid.

#### (3) Order of crediting payments

For purposes of paragraph (2)(B), a payment of estimated tax shall be credited against unpaid required installments in the order in which such installments are required to be paid.

#### (c) Number of required installments; due dates

For purposes of this section—

#### (1) Payable in 4 installments

There shall be 4 required installments for each taxable year.

#### (2) Time for payment of installments

| **  In the case of the following    required installments:** | **The due date is:** |
| --- | --- |
| 1st | April 15 |
| 2nd | June 15 |
| 3rd | September 15 |
| 4th | January 15 of the following taxable year. |

required installments:

#### (d) Amount of required installments

For purposes of this section—

#### (1) Amount

#### (A) In general

Except as provided in paragraph (2), the amount of any required installment shall be 25 percent of the required annual payment.

#### (B) Required annual payment

For purposes of subparagraph (A), the term "required annual payment" means the lesser of—

(i) 90 percent of the tax shown on the return for the taxable year (or, if no return is filed, 90 percent of the tax for such year), or

(ii) 100 percent of the tax shown on the return of the individual for the preceding taxable year.

Clause (ii) shall not apply if the preceding taxable year was not a taxable year of 12 months or if the individual did not file a return for such preceding taxable year.

#### (C) Limitation on use of preceding year's tax

#### (i) In general

If the adjusted gross income shown on the return of the individual for the preceding taxable year beginning in any calendar year exceeds $150,000, clause (ii) of subparagraph (B) shall be applied by substituting "110 percent" for "100 percent".

#### (ii) Separate returns

In the case of a married individual (within the meaning of section 7703) who files a separate return for the taxable year for which the amount of the installment is being determined, clause (i) shall be applied by substituting "$75,000" for "$150,000".

#### (iii) Special rule

In the case of an estate or trust, adjusted gross income shall be determined as provided in section 67(e).

#### (2) Lower required installment where annualized income installment is less than amount determined under paragraph (1)

#### (A) In general

In the case of any required installment, if the individual establishes that the annualized income installment is less than the amount determined under paragraph (1)—

(i) the amount of such required installment shall be the annualized income installment, and

(ii) any reduction in a required installment resulting from the application of this subparagraph shall be recaptured by increasing the amount of the next required installment determined under paragraph (1) by the amount of such reduction (and by increasing subsequent required installments to the extent that the reduction has not previously been recaptured under this clause).

#### (B) Determination of annualized income installment

In the case of any required installment, the annualized income installment is the excess (if any) of—

(i) an amount equal to the applicable percentage of the tax for the taxable year computed by placing on an annualized basis the taxable income, alternative minimum taxable income, and adjusted self-employment income for months in the taxable year ending before the due date for the installment, over

(ii) the aggregate amount of any prior required installments for the taxable year.

#### (C) Special rules

For purposes of this paragraph—

#### (i) Annualization

The taxable income, alternative minimum taxable income, and adjusted self-employment income shall be placed on an annualized basis under regulations prescribed by the Secretary.

#### (ii) Applicable percentage

| **  In the case of the following   required installments:** | **The applicable percentage is:** |
| --- | --- |
| 1st | 22.5 |
| 2nd | 45 |
| 3rd | 67.5 |
| 4th | 90. |

required installments:

#### (iii) Adjusted self-employment income

The term "adjusted self-employment income" means self-employment income (as defined in section 1402(b)); except that section 1402(b) shall be applied by placing wages (within the meaning of section 1402(b)) for months in the taxable year ending before the due date for the installment on an annualized basis consistent with clause (i).

#### (D) Treatment of subpart F income

#### (i) In general

Any amounts required to be included in gross income under section 951(a) (and credits properly allocable thereto) shall be taken into account in computing any annualized income installment under subparagraph (B) in a manner similar to the manner under which partnership income inclusions (and credits properly allocable thereto) are taken into account.

#### (ii) Prior year safe harbor

If a taxpayer elects to have this clause apply to any taxable year—

(I) clause (i) shall not apply, and

(II) for purposes of computing any annualized income installment for such taxable year, the taxpayer shall be treated as having received ratably during such taxable year items of income and credit described in clause (i) in an amount equal to the amount of such items shown on the return of the taxpayer for the preceding taxable year (the second preceding taxable year in the case of the first and second required installments for such taxable year).

#### (e) Exceptions

#### (1) Where tax is small amount

No addition to tax shall be imposed under subsection (a) for any taxable year if the tax shown on the return for such taxable year (or, if no return is filed, the tax), reduced by the credit allowable under section 31, is less than $1,000.

#### (2) Where no tax liability for preceding taxable year

No addition to tax shall be imposed under subsection (a) for any taxable year if—

(A) the preceding taxable year was a taxable year of 12 months,

(B) the individual did not have any liability for tax for the preceding taxable year, and

(C) the individual was a citizen or resident of the United States throughout the preceding taxable year.

#### (3) Waiver in certain cases

#### (A) In general

No addition to tax shall be imposed under subsection (a) with respect to any underpayment to the extent the Secretary determines that by reason of casualty, disaster, or other unusual circumstances the imposition of such addition to tax would be against equity and good conscience.

#### (B) Newly retired or disabled individuals

No addition to tax shall be imposed under subsection (a) with respect to any underpayment if the Secretary determines that—

(i) the taxpayer—

(I) retired after having attained age 62, or

(II) became disabled,

in the taxable year for which estimated payments were required to be made or in the taxable year preceding such taxable year, and

(ii) such underpayment was due to reasonable cause and not to willful neglect.

#### (f) Tax computed after application of credits against tax

For purposes of this section, the term "tax" means—

(1) the tax imposed by chapter 1 (other than any increase in such tax by reason of section 143(m)), plus

(2) the tax imposed by chapter 2, plus

(3) the tax imposed by chapter 2A, minus

(4) the credits against tax provided by part IV of subchapter A of chapter 1, other than the credit against tax provided by section 31 (relating to tax withheld on wages).

#### (g) Application of section in case of tax withheld on wages

#### (1) In general

For purposes of applying this section, the amount of the credit allowed under section 31 for the taxable year shall be deemed a payment of estimated tax, and an equal part of such amount shall be deemed paid on each due date for such taxable year, unless the taxpayer establishes the dates on which all amounts were actually withheld, in which case the amounts so withheld shall be deemed payments of estimated tax on the dates on which such amounts were actually withheld.

#### (2) Separate application

The taxpayer may apply paragraph (1) separately with respect to—

(A) wage withholding, and

(B) all other amounts withheld for which credit is allowed under section 31.

#### (h) Special rule where return filed on or before January 31

If, on or before January 31 of the following taxable year, the taxpayer files a return for the taxable year and pays in full the amount computed on the return as payable, then no addition to tax shall be imposed under subsection (a) with respect to any underpayment of the 4th required installment for the taxable year.

#### (i) Special rules for farmers and fishermen

For purposes of this section—

#### (1) In general

If an individual is a farmer or fisherman for any taxable year—

(A) there shall be only 1 required installment for the taxable year,

(B) the due date for such installment shall be January 15 of the following taxable year,

(C) the amount of such installment shall be equal to the required annual payment determined under subsection (d)(1)(B) by substituting "662/3 percent" for "90 percent" and without regard to subparagraph (C) of subsection (d)(1), and

(D) subsection (h) shall be applied—

(i) by substituting "March 1" for "January 31", and

(ii) by treating the required installment described in subparagraph (A) of this paragraph as the 4th required installment.

#### (2) Farmer or fisherman defined

An individual is a farmer or fisherman for any taxable year if—

(A) the individual's gross income from farming or fishing (including oyster farming) for the taxable year is at least 662/3 percent of the total gross income from all sources for the taxable year, or

(B) such individual's gross income from farming or fishing (including oyster farming) shown on the return of the individual for the preceding taxable year is at least 662/3 percent of the total gross income from all sources shown on such return.

#### (j) Special rules for nonresident aliens

In the case of a nonresident alien described in section 6072(c):

#### (1) Payable in 3 installments

There shall be 3 required installments for the taxable year.

#### (2) Time for payment of installments

The due dates for required installments under this subsection shall be determined under the following table:

| **  In the case of the following    required installments:** | **The due date is:** |
| --- | --- |
| 1st | June 15 |
| 2nd | September 15 |
| 3rd | January 15 of the following taxable year. |

required installments:

#### (3) Amount of required installments

#### (A) First required installment

In the case of the first required installment, subsection (d) shall be applied by substituting "50 percent" for "25 percent" in subsection (d)(1)(A).

#### (B) Determination of applicable percentage

The applicable percentage for purposes of subsection (d)(2) shall be determined under the following table:

| ** In the case of the following  required installments:** | **The applicable percentage is:** |
| --- | --- |
| 1st | 22.5 |
| 2nd | 45 |
| 3rd | 67.5 |
| 4th | 90. |

required installments:

#### (k) Fiscal years and short years

#### (1) Fiscal years

In applying this section to a taxable year beginning on any date other than January 1, there shall be substituted, for the months specified in this section, the months which correspond thereto.

#### (2) Short taxable year

This section shall be applied to taxable years of less than 12 months in accordance with regulations prescribed by the Secretary.

#### (l) Estates and trusts

#### (1) In general

Except as otherwise provided in this subsection, this section shall apply to any estate or trust.

#### (2) Exception for estates and certain trusts

With respect to any taxable year ending before the date 2 years after the date of the decedent's death, this section shall not apply to—

(A) the estate of such decedent, or

(B) any trust—

(i) all of which was treated (under subpart E of part I of subchapter J of chapter 1) as owned by the decedent, and

(ii) to which the residue of the decedent's estate will pass under his will (or, if no will is admitted to probate, which is the trust primarily responsible for paying debts, taxes, and expenses of administration).

#### (3) Exception for charitable trusts and private foundations

This section shall not apply to any trust which is subject to the tax imposed by section 511 or which is a private foundation.

#### (4) Special rule for annualizations

In the case of any estate or trust to which this section applies, subsection (d)(2)(B)(i) shall be applied by substituting "ending before the date 1 month before the due date for the installment" for "ending before the due date for the installment".

#### (m) Special rule for Medicare tax

For purposes of this section, the tax imposed under section 3101(b)(2) (to the extent not withheld) shall be treated as a tax imposed under chapter 2.

#### (n) Regulations

The Secretary shall prescribe such regulations as may be necessary to carry out the purposes of this section.

(Aug. 16, 1954, ch. 736, 68A Stat. 823; Pub. L. 87–682, §1(a)(4), Sept. 25, 1962, 76 Stat. 575; Pub. L. 89–368, title I, §§102(b)(1)–(3), 103(a), Mar. 15, 1966, 80 Stat. 62–64; Pub. L. 91–172, title III, §301(b)(13), Dec. 30, 1969, 83 Stat. 586; Pub. L. 92–5, title II, §203(b)(7), Mar. 17, 1971, 85 Stat. 11; Pub. L. 92–336, title II, §203(b)(7), July 1, 1972, 86 Stat. 420; Pub. L. 93–66, title II, §203(b)(7), (d), July 9, 1973, 87 Stat. 153; Pub. L. 93–233, §5(b)(7), (d), Dec. 31, 1973, 87 Stat. 954; Pub. L. 93–625, §7(c), Jan. 3, 1975, 88 Stat. 2115; Pub. L. 94–455, title XIX, §1906(a)(35), (b)(13)(A), Oct. 4, 1976, 90 Stat. 1829, 1834; Pub. L. 95–30, title I, §102(b)(16), May 23, 1977, 91 Stat. 139; Pub. L. 95–600, title IV, §421(e)(9), Nov. 6, 1978, 92 Stat. 2877; Pub. L. 97–34, title VI, §601(a)(6)(A), title VII, §725(b), (c)(5), Aug. 13, 1981, 95 Stat. 336, 346; Pub. L. 97–248, title II, §207(d)(7), formerly §207(c)(7), title III, §§307(a)(14), 308(a), 328(a), Sept. 3, 1982, 96 Stat. 420, 590, 591, 618, renumbered §207(d)(7), Pub. L. 97–448, title III, §306(a)(1)(A)(i), Jan. 12, 1983, 96 Stat. 2400; Pub. L. 97–448, title I, §§106(a)(4)(C), 107(c)(1), title II, §201(j)(3), Jan. 12, 1983, 96 Stat. 2390, 2391, 2396; Pub. L. 98–67, title I, §102(a), Aug. 5, 1983, 97 Stat. 369; Pub. L. 98–369, div. A, title IV, §411, July 18, 1984, 98 Stat. 788; Pub. L. 99–514, title XIV, §1404(a), title XV, §§1511(c)(14), 1541(a), (b), title XVIII, §1841, Oct. 22, 1986, 100 Stat. 2713, 2745, 2751, 2852; Pub. L. 100–418, title I, §1941(b)(6)(A), Aug. 23, 1988, 102 Stat. 1324; Pub. L. 100–647, title I, §1014(d)(1), (2), title IV, §4005(g)(5), Nov. 10, 1988, 102 Stat. 3560, 3651; Pub. L. 101–239, title VII, §7811(j)(5), (6), Dec. 19, 1989, 103 Stat. 2411, 2412; Pub. L. 102–164, title IV, §403(a), (b), Nov. 15, 1991, 105 Stat. 1062, 1064; Pub. L. 103–66, title XIII, §13214(a), (b), Aug. 10, 1993, 107 Stat. 475; Pub. L. 103–465, title VII, §711(b), Dec. 8, 1994, 108 Stat. 4998; Pub. L. 105–34, title X, §1091(a), title XII, §1202(a), Aug. 5, 1997, 111 Stat. 962, 994; Pub. L. 105–277, div. J, title II, §2003(a), Oct. 21, 1998, 112 Stat. 2681–901; Pub. L. 106–170, title V, §531(a), Dec. 17, 1999, 113 Stat. 1928; Pub. L. 111–5, div. B, title I, §1212, Feb. 17, 2009, 123 Stat. 336; Pub. L. 111–152, title I, §1402(a)(2), (b)(2), Mar. 30, 2010, 124 Stat. 1062, 1063; Pub. L. 115–141, div. U, title IV, §401(a)(301), (302), (b)(48), (49), (d)(1)(D)(xix), Mar. 23, 2018, 132 Stat. 1199, 1204, 1205, 1208.)

#### **Editorial Notes**

#### Amendments

2018—Subsec. (a). Pub. L. 115–141, §401(a)(301), substituted "chapter 1, the tax" for "chapter 1 the tax" in introductory provisions.

Subsec. (d)(1)(C)(i). Pub. L. 115–141, §401(b)(48), substituted "by substituting '110 percent' for '100 percent'." for "by substituting the applicable percentage for '100 percent'. For purposes of the preceding sentence, the applicable percentage shall be determined in accordance with the following table:", table setting out applicable percentages for preceding taxable years 1998 to 2002 and thereafter, and concluding provisions "This clause shall not apply in the case of a preceding taxable year beginning in calendar year 1997."

Subsec. (d)(1)(D). Pub. L. 115–141, §401(b)(49), struck out subpar. (D) which set out a special rule for taxable years beginning in 2009.

Subsec. (d)(2)(D). Pub. L. 115–141, §401(d)(1)(D)(xix)(II), struck out "and section 936" before "income" in heading.

Subsec. (d)(2)(D)(i). Pub. L. 115–141, §401(d)(1)(D)(xix)(I), struck out "936(h) or" before "951(a)".

Subsec. (f)(3). Pub. L. 115–141, §401(a)(302), substituted "tax" for "taxes".

2010—Subsec. (a). Pub. L. 111–152, §1402(a)(2)(A), substituted "the tax under chapter 2, and the tax under chapter 2A" for "and the tax under chapter 2" in introductory provisions.

Subsec. (f)(2). Pub. L. 111–152, §1402(a)(2)(B)(i), substituted "plus" for "minus".

Subsec. (f)(3), (4). Pub. L. 111–152, §1402(a)(2)(B)(ii), added par. (3) and redesignated former par. (3) as (4).

Subsecs. (m), (n). Pub. L. 111–152, §1402(b)(2), added subsec. (m) and redesignated former subsec. (m) as (n).

2009—Subsec. (d)(1)(D). Pub. L. 111–5 added subpar. (D).

1999—Subsec. (d)(1)(C)(i). Pub. L. 106–170 in table substituted items assigning applicable percentages of 108.6 for 1999 and 110 for 2000 for item assigning applicable percentage of 106 for 1999 or 2000.

1998—Subsec. (d)(1)(C)(i). Pub. L. 105–277 in table substituted items assigning applicable percentages of 105 for 1998 and 106 for 1999 or 2000 for item assigning applicable percentage of 105 for 1998, 1999, or 2000.

1997—Subsec. (d)(1)(C)(i). Pub. L. 105–34, §1091(a), reenacted heading without change and amended text generally. Prior to amendment, text read as follows: "If the adjusted gross income shown on the return of the individual for the preceding taxable year exceeds $150,000, clause (ii) of subparagraph (B) shall be applied by substituting '110 percent' for '100 percent'."

Subsec. (e)(1). Pub. L. 105–34, §1202(a), substituted "$1,000" for "$500".

1994—Subsec. (d)(2)(D). Pub. L. 103–465 added subpar. (D).

1993—Subsec. (d)(1)(C) to (F). Pub. L. 103–66, §13214(a), added subpar. (C) and struck out former subpars. (C) to (F) which related to limitation on use of preceding year's tax, modified adjusted gross income for current year, qualified pass-thru item, and other definitions and special rules, respectively.

Subsec. (j)(3)(A). Pub. L. 103–66, §13214(b)(1), struck out before period at end "and subsection (d)(1)(C)(iii) shall not apply".

Subsec. (l)(4). Pub. L. 103–66, §13214(b)(2), substituted "subsection (d)(2)(B)(i)" for "paragraphs (1)(C)(iv) and (2)(B)(i) of subsection (d)".

1991—Subsec. (d)(1)(C) to (F). Pub. L. 102–164, §403(a), added subpars. (C) to (F).

Subsec. (i)(1)(C). Pub. L. 102–164, §403(b)(1), amended subpar. (C) generally. Prior to amendment, subpar. (C) read as follows: "the amount of such installment shall be equal to the required annual payment (determined under subsection (d)(1)(B) by substituting '662/3 percent' for '90 percent', and".

Subsec. (j)(3)(A). Pub. L. 102–164, §403(b)(2), inserted before period at end "and subsection (d)(1)(C)(iii) shall not apply".

Subsec. (l)(4). Pub. L. 102–164, §403(b)(3), substituted "paragraphs (l)(C)(iv) and (2)(B)(i) of subsection (d)" for "subsection (d)(2)(B)(i)".

1989—Subsec. (l)(1). Pub. L. 101–239, §7811(j)(5), substituted "this section shall" for "this subsection shall".

Subsec. (l)(2)(B)(ii). Pub. L. 101–239, §7811(j)(6), inserted before period at end "(or, if no will is admitted to probate, which is the trust primarily responsible for paying debts, taxes, and expenses of administration)".

1988—Subsec. (f)(1). Pub. L. 100–647, §4005(g)(5), inserted "(other than any increase in such tax by reason of section 143(m))" after "chapter 1".

Subsec. (f)(3). Pub. L. 100–418 amended par. (3) generally. Prior to amendment par. (3) read as follows: "the sum of—

"(A) the credits against tax allowed by part IV of subchapter A of chapter 1, other than the credit against tax provided by section 31 (relating to tax withheld on wages), plus

"(B) to the extent allowed under regulations prescribed by the Secretary, any overpayment of the tax imposed by section 4986 (determined without regard to section 4995(a)(4)(B))."

Subsec. (l). Pub. L. 100–647, §1014(d)(2), substituted "Estates and trusts" for "Trusts and certain estates" in heading and amended text generally. Prior to amendment, text read as follows: "This section shall apply to—

"(1) any trust, and

"(2) any estate with respect to any taxable year ending 2 or more years after the date of the death of the decedent's death."

Pub. L. 100–647, §1014(d)(1), made clarifying amendment to directory language of Pub. L. 99–514, §1404(a), to reflect prior redesignation of subsec. (k) as (l) by section 1841 of Pub. L. 99–514, see 1986 Amendment note below.

1986—Subsec. (a)(1). Pub. L. 99–514, §1511(c)(14), substituted "the underpayment rate established under section 6621" for "the applicable annual rate established under section 6621".

Subsec. (d)(1)(B)(i). Pub. L. 99–514, §1541(a), substituted "90 percent" for "80 percent" in two places.

Subsec. (d)(2)(C)(ii). Pub. L. 99–514, §1541(b)(1), in table of applicable percentages increased applicable percentages from "20" to "22.5", from "40" to "45", from "60" to "67.5", and from "80" to "90", respectively.

Subsec. (i)(1)(C). Pub. L. 99–514, §1541(b)(2), substituted "90 percent" for "80 percent".

Subsec. (j). Pub. L. 99–514, §1841, added subsec. (j). Former subsec. (j) redesignated (k).

Subsec. (j)(3)(B). Pub. L. 99–514, §1541(b)(3), which directed the amendment of the table in subpar. (B) by substituting "45" for "40", "65.5" for "60", and "90" for "80", could not be executed because the higher figures appear in the text as enacted by section 1841 of Pub. L. 99–514.

Subsec. (k). Pub. L. 99–514, §1841, redesignated former subsec. (j) as (k). Former subsec. (k) redesignated (l).

Subsec. (l). Pub. L. 99–514, §1404(a), as amended by Pub. L. 100–647, §1014(d)(1), amended subsec. (l) generally. Prior to amendment, subsec. (l) read as follows: "This section shall not apply to any estate or trust."

Pub. L. 99–514, §1841, redesignated subsec. (k) as (l). Former subsec. (l) redesignated (m).

Subsec. (m). Pub. L. 99–514, §1841, redesignated former subsec. (l) as (m).

1984—Subsec. (a). Pub. L. 98–369 amended subsec. (a) generally, setting out the exception provision as initial phrase, previously set out as second phrase, substituting "subsection (d)" for "this section"; and substituting "determined by applying—" and provisions designated cls. (1) to (3) for provisions reading "determined at an annual rate established under section 6621 upon the amount of the underpayment (determined under subsection (b)) for the period of the underpayment (determined under subsection (c)))".

Subsec. (b). Pub. L. 98–369 amended subsec. (b) generally, substituting provisions relating to amount and period of underpayment for provisions relating only to amount of underpayment.

Subsec. (c). Pub. L. 98–369 amended subsec. (c) generally, substituting provisions relating to number of required installments and due dates for provisions respecting period of underpayment. See subsec. (b)(2) of this section.

Subsec. (d). Pub. L. 98–369 amended subsec. (d) generally, substituting provisions relating to amount of required installments for provisions designated "Exception" and describing conditions for nonimposition of an addition to the tax with respect to any underpayment of any installment.

Subsec. (e). Pub. L. 98–369 amended subsec. (e) generally, substituting provisions relating to exceptions for provisions relating to application of section in case of tax withheld on wages. See subsec. (g) of this section.

Subsec. (f). Pub. L. 98–369 amended subsec. (f) generally, substituting provisions relating to tax computed after application of credits against tax for provisions relating to exception where tax is small amount. See subsec. (e)(1) of this section.

Subsec. (g). Pub. L. 98–369 amended subsec. (g) generally, substituting provisions relating to application of section in case of tax withheld on wages for provisions relating to tax computed after application of credits against tax. See subsec. (f) of this section.

Subsec. (h). Pub. L. 98–369 amended subsec. (h) generally, substituting provisions relating to special rule for returns filed on or before January 31 for provisions relating to exception for no tax liability for preceding taxable year. See subsec. (e)(2) of this section.

Subsec. (i). Pub. L. 98–369 amended subsec. (i) generally, substituting provisions relating to special rules for farmers and fishermen for provisions relating to short taxable year. See subsec. (j)(2) of this section.

Subsecs. (j) to (l). Pub. L. 98–369, in amending section generally, added subsecs. (j) to (l).

1983—Subsec. (e)(1). Pub. L. 98–67 repealed amendments made by Pub. L. 97–248. See 1982 Amendment note below.

Subsec. (f)(1). Pub. L. 97–448, §107(c)(1), inserted ", reduced by the credit allowable under section 31," before "is less than".

Subsec. (g)(3)(B). Pub. L. 97–448, §201(j)(3), amended subpar. (B) generally. Prior to amendment, subpar. (B) read as follows: "to the extent allowed under regulations prescribed by the Secretary, any amount which is treated under section 6429 or 6430 as an overpayment of the tax imposed by section 4986".

Pub. L. 97–448, §106(a)(4)(C), inserted "or 6430" after "section 6429".

1982—Subsec. (e)(1). Pub. L. 97–248, §§307(a)(14), 308(a), provided that, applicable to payments of interest, dividends, and patronage dividends paid or credited after June 30, 1983, par. (1) is amended by inserting ", interest, dividends, and patronage dividends" after "tax withheld at source on wages". Section 102(a), (b) of Pub. L. 98–67, title I, Aug. 5, 1983, 97 Stat. 369, repealed subtitle A (§§301–308) of title III of Pub. L. 97–248 as of the close of June 30, 1983, and provided that the Internal Revenue Code of 1954 [now 1986] [this title] shall be applied and administered (subject to certain exceptions) as if such subtitle A (and the amendments made by such subtitle A) had not been enacted.

Subsec. (g). Pub. L. 97–248, §328(a)(2), substituted "(f), and (h)" for "and (f)".

Subsec. (g)(1). Pub. L. 97–248, §201(d)(7), formerly §201(c)(7), substituted "section 55" for "section 55 or 56".

Subsec. (g)(3). Pub. L. 97–248, §§307(a)(14), 308(a), provided that, applicable to payments of interest, dividends, and patronage dividends paid or credited after June 30, 1983, subsec. (g)(3) is amended by inserting ", interest, dividends, and patronage dividends" after "tax withheld at source on wages". Section 102(a), (b) of Pub. L. 98–67, title I, Aug. 5, 1983, 97 Stat. 369, repealed subtitle A (§§301–308) of title III of Pub. L. 97–248 as of the close of June 30, 1983, and provided that the Internal Revenue Code of 1954 [now 1986] [this title] shall be applied and administered (subject to certain exceptions) as if such subtitle A (and the amendments made by such subtitle A) had not been enacted.

Subsecs. (h), (i). Pub. L. 97–248, §328(a)(1), added subsec. (h) and redesignated former subsec. (h) as (i).

1981—Subsec. (f). Pub. L. 97–34, §725(b), added subsec. (f). Former subsec. (f) redesignated (g).

Subsec. (f)(3). Pub. L. 97–34, §601(a)(6)(A), inserted "the sum of—" after "(3)", designated former par. (3) as subpar. (A), and added subpar. (B).

Subsecs. (g), (h). Pub. L. 97–34, §§601(a)(6)(A), 725(b), (c)(5), redesignated former subsec. (f) as (g), inserted reference to subsec. (f) in introductory text, and "the sum of—" after "(3)", designated former par. (3) as subpar. (A), and added subpar. (B). Former subsec. (g) redesignated (h).

1978—Subsec. (f)(1). Pub. L. 95–600 substituted "section 55 or 56" for "section 56".

1977—Subsec. (d)(2)(A). Pub. L. 95–30 substituted provisions directing that the placement of taxable income on an annualized basis be accomplished under regulations prescribed by the Secretary for provisions which had spelled out in detail the formula under which taxable income would be placed on an annualized basis.

1976—Subsec. (g). Pub. L. 94–455, §1906(b)(13)(A), struck out "or his delegate" after "Secretary".

Subsec. (h). Pub. L. 94–455, §1906(a)(35), struck out subsec. (h) which provided that this section shall apply to taxable years beginning after Dec. 31, 1954 and that section 294(d) of the Internal Revenue Code of 1939 shall continue in force with respect to taxable years beginning before Jan. 1, 1955.

1975—Subsec. (a). Pub. L. 93–625 substituted "an annual rate established under section 6621" for "the rate of 6 percent per annum".

1973—Subsec. (d)(2)(B)(ii). Pub. L. 93–233, §5(b)(7), effective with respect to taxable years beginning after 1973, substituted "$13,200" for "$12,600".

Pub. L. 93–233, §5(d), applicable only with respect to remuneration paid after, and taxable years beginning after, 1973 (as provided in section 5(e) of Pub. L. 93–233, set out as an Effective Date of 1973 Amendments note under section 409 of Title 42, The Public Health and Welfare), amended section 203(b)(7)(C) of Pub. L. 92–336 (set out as 1973 Amendment note below), substituting "$13,200" for "$12,600". See, also, 1973 Amendment note below.

Pub. L. 93–66, §203(b)(7), effective with respect to taxable years beginning after 1973, substituted "$12,600" for "$12,000".

Pub. L. 93–66, §203(d), applicable only with respect to remuneration paid after, and taxable years beginning after, 1973 (as provided in section 203(e) of Pub. L. 93–66, set out as an Effective Date of 1973 Amendments note under section 409 of Title 42, The Public Health and Welfare), amended section 203(b)(7)(C) of Pub. L. 92–336 (set out as 1972 Amendment note below, substituting "$12,600" for "$12,000". See, also, such 1972 Amendment note below.

1972—Subsec. (d)(2)(B)(ii). Pub. L. 92–336, §203(b)(7)(A) substituted "$10,800" for "$9,000".

Pub. L. 92–336, §203(b)(7)(B), effective with respect to taxable years beginning after 1973, substituted "$12,000" for "$10,800".

Pub. L. 92–336, §203(b)(7)(C), effective with respect to taxable years beginning after 1974, substituted "(I) an amount equal to the contribution and benefit base (as determined under section 230 of the Social Security Act) which is effective for the calendar year in which the taxable year begins, over (II)" for "$12,000 over".

1971—Subsec. (d)(2)(B)(ii). Pub. L. 92–5 substituted "$9,000" for "$6,600".

1969—Subsec. (f)(1). Pub. L. 91–172 inserted "(other than by section 56)" after "chapter 1".

1966—Subsec. (a). Pub. L. 89–368, §102(b)(1), inserted "and the tax under chapter 2" after "chapter 1".

Subsec. (b). Pub. L. 89–368, §103(a), substituted "80 percent" for "70 percent" whenever appearing.

Subsec. (d). Pub. L. 89–368, §§102(b)(2), 103(a), inserted requirement that, for purposes of applying the annualization exception, the tax on adjusted self-employment income be included in determining if the net earnings from self-employment for the taxable year equal or exceed $400, inserted definition of "adjusted self-employment income", inserted a requirement that, for purposes of determining the applicability of the 90 percent exception, the tax on actual self-employment income be included, and substituted "80 percent" for "70 percent" wherever appearing.

Subsec. (f). Pub. L. 89–368, §102(b)(3), inserted tax imposed by chapter 2 to definition of "tax".

1962—Subsecs. (b), (d)(1)(C). Pub. L. 87–682 inserted "or fishing" after "from farming" wherever appearing.

#### **Statutory Notes and Related Subsidiaries**

#### Effective Date of 2010 Amendment

Amendment by section 1402(a)(2) of Pub. L. 111–152 applicable to taxable years beginning after Dec. 31, 2012, see section 1402(a)(4) of Pub. L. 111–152, set out as an Effective Date note under section 1411 of this title.

Amendment by section 1402(b)(2) of Pub. L. 111–152 applicable with respect to remuneration received, and taxable years beginning after, Dec. 31, 2012, see section 1402(b)(3) of Pub. L. 111–152, set out as a note under section 1401 of this title.

#### Effective Date of 1999 Amendment

Pub. L. 106–170, title V, §531(b), Dec. 17, 1999, 113 Stat. 1928, provided that: "The amendment made by this section [amending this section] shall apply with respect to any installment payment for taxable years beginning after December 31, 1999."

#### Effective Date of 1998 Amendment

Pub. L. 105–277, div. J, title II, §2003(b), Oct. 21, 1998, 112 Stat. 2681–902, provided that: "The amendment made by this section [amending this section] shall apply with respect to any installment payment for taxable years beginning after December 31, 1999."

#### Effective Date of 1997 Amendment

Pub. L. 105–34, title X, §1091(b), Aug. 5, 1997, 111 Stat. 962, provided that: "The amendment made by this section [amending this section] shall apply with respect to any installment payment for taxable years beginning after December 31, 1997."

Pub. L. 105–34, title XII, §1202(b), Aug. 5, 1997, 111 Stat. 994, provided that: "The amendments made by this section [amending this section] shall apply to taxable years beginning after December 31, 1997."

#### Effective Date of 1994 Amendment

Pub. L. 103–465, title VII, §711(c), Dec. 8, 1994, 108 Stat. 4999, provided that: "The amendments made by this section [amending this section and section 6655 of this title] shall apply for purposes of determining underpayments of estimated tax for taxable years beginning after December 31, 1994."

#### Effective Date of 1993 Amendment

Pub. L. 103–66, title XIII, §13214(c), Aug. 10, 1993, 107 Stat. 475, provided that: "The amendments made by this section [amending this section] shall apply to taxable years beginning after December 31, 1993."

#### Effective Date of 1991 Amendment

Pub. L. 102–164, title IV, §403(c), Nov. 15, 1991, 105 Stat. 1064, provided that: "The amendments made by this section [amending this section] shall apply to taxable years beginning after December 31, 1991."

#### Effective Date of 1989 Amendment

Amendment by Pub. L. 101–239 effective, except as otherwise provided, as if included in the provision of the Technical and Miscellaneous Revenue Act of 1988, Pub. L. 100–647, to which such amendment relates, see section 7817 of Pub. L. 101–239, set out as a note under section 1 of this title.

#### Effective Date of 1988 Amendments

Amendment by section 1014(d)(1), (2) of Pub. L. 100–647 effective, except as otherwise provided, as if included in the provision of the Tax Reform Act of 1986, Pub. L. 99–514, to which such amendment relates, see section 1019(a) of Pub. L. 100–647, set out as a note under section 1 of this title.

Amendment by section 4005(g)(5) of Pub. L. 100–647 applicable to financing provided, and mortgage credit certificates issued, after Dec. 31, 1990, with certain exceptions, see section 4005(h)(3) of Pub. L. 100–647, set out as a note under section 143 of this title.

Amendment by Pub. L. 100–418 applicable to crude oil removed from the premises on or after Aug. 23, 1988, see section 1941(c) of Pub. L. 100–418, set out as a note under section 164 of this title.

#### Effective Date of 1986 Amendments

Pub. L. 100–203, title X, §10303(a), Dec. 22, 1987, 101 Stat. 1330–430, provided that: "Notwithstanding section 1541(c) of the Tax Reform Act of 1986 [section 1541(c) of Pub. L. 99–514, set out below], the amendments made by section 1541 of such Act [amending this section] shall apply only to taxable years beginning after December 31, 1987."

Amendment by section 1404(a) of Pub. L. 99–514 applicable to taxable years beginning after Dec. 31, 1986, see section 1404(d) of Pub. L. 99–514, set out as a note under section 643 of this title.

Amendment by section 1511(c)(14) of Pub. L. 99–514 applicable for purposes of determining interest for periods after Dec. 31, 1986, see section 1511(d) of Pub. L. 99–514, set out as a note under section 47 of this title.

Pub. L. 99–514, title XV, §1541(c), Oct. 22, 1986, 100 Stat. 2751, provided that: "The amendments made by this section [amending this section] shall apply to taxable years beginning after December 31, 1986." [See section 10303(a) of Pub. L. 100–203, set out above.]

Amendment by section 1841 of Pub. L. 99–514 effective, except as otherwise provided, as if included in the provisions of the Tax Reform Act of 1984, Pub. L. 98–369, div. A, to which such amendment relates, see section 1881 of Pub. L. 99–514, set out as a note under section 48 of this title.

#### Effective Date of 1984 Amendment

Pub. L. 98–369, div. A, title IV, §414(a), July 18, 1984, 98 Stat. 793, as amended by Pub. L. 99–514, §2, Oct. 22, 1986, 100 Stat. 2095, provided that:

"(1) In general.—The amendments made by sections 411 and 412 [amending this section and sections 871, 1403, 6012, 6020, 6201, 6362, 6601, 6651, 7203, 7216, and 7701 of this title and repealing sections 6015, 6073, and 6153 of this title] shall apply with respect to taxable years beginning after December 31, 1984.

"(2) Waiver authority.—The provisions of paragraph (3) of section 6654(e) of the Internal Revenue Code of 1986 [formerly I.R.C. 1954] (as amended by section 411) shall also apply with respect to underpayments for taxable years beginning in 1984."

#### Effective Date of 1983 Amendment

Amendment by section 106(a)(4)(C) of Pub. L. 97–448 effective Jan. 1, 1982, see section 106(a)(4)(E)(ii) of Pub. L. 97–448, set out as an Effective Date note under section 6430 of this title.

Amendment by title I of Pub. L. 97–448 effective, except as otherwise provided, as if it had been included in the provision of the Economic Recovery Tax Act of 1981, Pub. L. 97–34, to which such amendment relates, see section 109 of Pub. L. 97–448, set out as a note under section 1 of this title.

Amendment by title II of Pub. L. 97–448 effective, except as otherwise provided, as if it had been included in the provision of the Crude Oil Windfall Profit Tax Act of 1980, Pub. L. 96–223, to which such amendment relates, see section 203(a), (b) of Pub. L. 97–448, set out as a note under section 6652 of this title.

#### Effective Date of 1982 Amendment

Amendment by section 201(d)(7) of Pub. L. 97–248 applicable to taxable years beginning after Dec. 31, 1982, see section 201(e)(1) of Pub. L. 97–248, set out as a note under section 5 of this title.

Pub. L. 97–248, title III, §328(c), Sept. 3, 1982, 96 Stat. 618, provided that: "The amendments made by this section [amending this section and sections 6015, 6073, and 6153 of this title] shall apply to taxable years beginning after December 31, 1982."

#### Effective Date of 1981 Amendment

Pub. L. 97–34, title VI, §601(c)(1), (2), Aug. 13, 1981, 95 Stat. 337, provided that:

"(1) Except as provided in paragraph (2), subsection (a) [amending this section and sections 6429 and 6655 of this title] shall take effect on January 1, 1981.

"(2) The amendments made by paragraph (6) of subsection (a) [amending this section and section 6655 of this title] shall take effect on January 1, 1980."

Amendment by section 725(b), (c)(5) of Pub. L. 97–34 applicable to estimated tax for taxable years beginning after Dec. 31, 1980, see section 725(d) of Pub. L. 97–34, set out as a note under section 871 of this title.

#### Effective Date of 1978 Amendment

Amendment by Pub. L. 95–600 applicable to taxable years beginning after Dec. 31, 1978, see section 421(g) of Pub. L. 95–600, set out as a note under section 5 of this title.

#### Effective Date of 1977 Amendment

Amendment by Pub. L. 95–30 applicable to taxable years beginning after Dec. 31, 1976, see section 106(a) of Pub. L. 95–30, set out as a note under section 1 of this title.

#### Effective Date of 1976 Amendment

Amendment by Pub. L. 94–455 effective first day of first month which begins more than 90 days after Oct. 4, 1976, see section 1906(d)(1) of Pub. L. 94–455, set out as a note under section 6013 of this title.

#### Effective Date of 1975 Amendment

Amendment by Pub. L. 93–625 effective July 1, 1975, and applicable to amounts outstanding on such date or arising thereafter, see section 7(e) of Pub. L. 93–625, set out as an Effective Date note under section 6621 of this title.

#### Effective Date of 1973 Amendments

Amendment by Pub. L. 93–233 applicable only with respect to remuneration paid after, and taxable years beginning after, 1973, see section 5(e) of Pub. L. 93–233, set out as a note under section 409 of Title 42, The Public Health and Welfare.

Amendment by Pub. L. 93–66 applicable only with respect to remuneration paid after, and taxable years beginning after, 1973, see section 203(e) of Pub. L. 93–66, set out as a note under section 409 of Title 42.

#### Effective Date of 1972 Amendment

Amendment by Pub. L. 92–336 applicable only with respect to taxable years beginning after 1972, see section 203(c) of Pub. L. 92–336, set out as a note under section 409 of Title 42, The Public Health and Welfare.

#### Effective Date of 1971 Amendment

Amendment by Pub. L. 92–5 applicable only with respect to taxable years beginning after 1971, see section 203(c) of Pub. L. 92–5, set out as a note under section 409 of Title 42, The Public Health and Welfare.

#### Effective Date of 1969 Amendment

Amendment by Pub. L. 91–172 applicable to taxable years ending after Dec. 31, 1969, see section 301(c) of Pub. L. 91–172, set out as a note under section 5 of this title.

#### Effective Date of 1966 Amendment

Pub. L. 89–368, title I, §102(d), Mar. 15, 1966, 80 Stat. 64, provided that: "The amendments made by subsections (a) amending section 6015 of this title], (b) [amending this section and sections 1403, 6211, and 7701 of this title], and (c) [amending section 1402 of this title] shall apply with respect to taxable years beginning after December 31, 1966."

Pub. L. 89–368, title I, §103(b), Mar. 15, 1966, 80 Stat. 64, provided that: "The amendments made by subsection (a) [amending this section] shall apply with respect to taxable years beginning after December 31, 1966."

#### Effective Date of 1962 Amendment

Pub. L. 87–682, §2, Sept. 25, 1962, 76 Stat. 575, provided that: "The amendments made by the first section of this Act [amending this section and sections 6015, 6073, and 6153 of this title] shall apply only with respect to taxable years beginning after December 31, 1962."

#### Savings Provision

For provisions that nothing in amendment by section 401(b)(48), (49), (d)(1)(D)(xix) of Pub. L. 115–141 be construed to affect treatment of certain transactions occurring, property acquired, or items of income, loss, deduction, or credit taken into account prior to Mar. 23, 2018, for purposes of determining liability for tax for periods ending after Mar. 23, 2018, see section 401(e) of Pub. L. 115–141, set out as a note under section 23 of this title.

#### Waiver of Estimated Tax Penalties for 1998 Underpayments

Pub. L. 105–206, §1(c), July 22, 1998, 112 Stat. 685, provided that: "No addition to tax shall be made under section 6654 or 6655 of the Internal Revenue Code of 1986 with respect to any underpayment of an installment required to be paid on or before the 30th day after the date of the enactment of this Act [July 22, 1998] to the extent such underpayment was created or increased by any provision of this Act [see Tables for classification]."

Pub. L. 105–34, §1(d), Aug. 5, 1997, 111 Stat. 788, provided that: "No addition to tax shall be made under section 6654 or 6655 of the Internal Revenue Code of 1986 for any period before January 1, 1998, for any payment the due date of which is before January 16, 1998, with respect to any underpayment attributable to such period to the extent such underpayment was created or increased by any provision of this Act [see Tables for classification]."

#### Underpayments of Estimated Tax for 1996

Pub. L. 104–188, title I, §1102, Aug. 20, 1996, 110 Stat. 1758, provided that: "No addition to the tax shall be made under section 6654 or 6655 of the Internal Revenue Code of 1986 (relating to failure to pay estimated tax) with respect to any underpayment of an installment required to be paid before the date of the enactment of this Act [Aug. 20, 1996] to the extent such underpayment was created or increased by any provision of this title [title I (§§1101–1954) of Pub. L. 104–188, see Tables for classification]."

#### Waiver of Estimated Penalties for 1993 Underpayments Attributable to Revenue Reconciliation Act of 1993

Pub. L. 103–66, title XIII, §13001(d), Aug. 10, 1993, 107 Stat. 416, provided that: "No addition to tax shall be made under section 6654 or 6655 of the Internal Revenue Code of 1986 for any period before April 16, 1994 (March 16, 1994, in the case of a corporation), with respect to any underpayment to the extent such underpayment was created or increased by any provision of this chapter [chapter 1 (§§13001–13444) of title XIII of Pub. L. 103–66, see Tables for classification]."

#### Waiver of Estimated Tax Penalties for Underpayments Attributable to Section 420(b)(4)(B) of This Title

No addition to tax to be made under this section for taxable year preceding taxpayer's first taxable year beginning after Dec. 31, 1990, with respect to any underpayment to the extent such underpayment was created or increased by reason of former section 420(b)(4)(B) of this title, see section 12011(c)(2) of Pub. L. 101–508, set out as an Effective Date note under section 420 of this title.

#### Waiver of Estimated Penalties for 1988 Underpayments Attributable to Technical and Miscellaneous Revenue Act of 1988

No addition to tax to be made under this section for any period before Apr. 16, 1989, with respect to any underpayment to the extent that such underpayment was created or increased by any provision of title I (§§1001–1019) or II (§§2001–2006) of Pub. L. 100–647, see section 1019(b) of Pub. L. 100–647, set out as an Effective Date of 1988 Amendment note under section 1 of this title.

#### Plan Amendments Not Required Until January 1, 1989

For provisions directing that if any amendments made by subtitle A or subtitle C of title XI [§§1101–1147 and 1171–1177] or title XVIII [§§1800–1899A] of Pub. L. 99–514 require an amendment to any plan, such plan amendment shall not be required to be made before the first plan year beginning on or after Jan. 1, 1989, see section 1140 of Pub. L. 99–514, as amended, set out as a note under section 401 of this title.

#### Waiver of Estimated Penalties for 1986 Underpayments Attributable to Tax Reform Act of 1986

Pub. L. 99–514, title XV, §1543, Oct. 22, 1986, 100 Stat. 2751, provided that: "No addition to tax shall be made under section 6654 or 6655 of the Internal Revenue Code of 1986 (relating to failure to pay estimated tax) for any period before April 16, 1987 (March 16, 1987, in the case of a taxpayer subject to section 6655 of such Code), with respect to any underpayment, to the extent such underpayment was created or increased by any provision of this Act [Pub. L. 99–514, see Tables for classification]."

#### Waiver of Estimated Tax Penalties

No addition to tax to be made under this section for any period before Apr. 16, 1985, with respect to any underpayment, to the extent that such underpayment was created or increased by any provision of Pub. L. 98–369, div. A, see section 1879(a) of Pub. L. 99–514, set out as a note under section 6655 of this title.

#### Increase in Section 31 Credit for Taxable Years Which Include any Portion of Period July 1, 1983, to December 31, 1983

For purposes of determining the amount of any addition to tax under this section with respect to any installment required to be paid before July 1, 1983, the amount of the credit allowed by section 31 of this title for any taxable year which includes any portion of the period beginning July 1, 1983, and ending December 31, 1983, to be increased by an amount equal to 10 percent of the aggregate amount of payments (1) which are received during the portion of such taxable year after June 30, 1983, and before January 1, 1984, and (2) which (but for the repeal of sections 3451 to 3456 of this title) would have been subject to withholding under sections 3451 to 3456 of this title (determined without regard to any exemption described in former section 3452 of this title, see section 102(d) of Pub. L. 98–67, set out as a note under section 3451 of this title.

#### Estimated Tax Underpayments Created or Increased by Tax Reform Act of 1976

Pub. L. 95–30, title III, §303, May 23, 1977, 91 Stat. 152, as amended by Pub. L. 99–514, §2, Oct. 22, 1986, 100 Stat. 2095, provided that: "No addition to the tax shall be made under section 6654 or 6655 of the Internal Revenue Code of 1986 [formerly I.R.C. 1954] (relating to failure to pay estimated income tax) for any period before April 16, 1977 (March 16, 1977, in the case of a taxpayer subject to section 6655), with respect to any underpayment, to the extent that such underpayment was created or increased by any provision of the Tax Reform Act of 1976 [Pub. L. 94–455]."

#### Waiver of Penalty for Underpayment of 1971 Estimated Income Tax

Pub. L. 92–178, title II, §207, Dec. 10, 1971, 85 Stat. 512, provided that subsec. (a) of this section did not apply to any taxable year beginning after Dec. 31, 1970 and ending before Jan. 1, 1972, if the gross income for such taxable year did not exceed $10,000 for a single individual other than head of household or a married individual filing separately, or if the gross income did not exceed $20,000 for a head of household, a surviving spouse, of married individuals filing jointly, or if the taxpayer had income from sources other than wages in excess of $200 or $400 in case of a joint return.

#### Declaration of Estimated Tax

With respect to taxable years beginning before Dec. 30, 1969, if a taxpayer is required to make a declaration, or to pay any amount of estimated tax by reason of amendments made by Pub. L. 91–172, such amount shall be paid ratably on each of the remaining installment dates for the taxable year beginning with the first installment date on or after Dec. 30, 1969; as to any declaration or payment of estimates tax before the first installment date, this section, and sections 6015, 6154, and 6655 of this title shall be applied without regard to amendments made by Pub. L. 91–172, see section 946(b) of Pub. L. 91–172, set out as a note under section 6153 of this title.

#### Tax Surcharge Extension; Declarations of Estimated Tax

Requirement of making a declaration or amended declaration or amended declaration of estimated tax or of payment of any amount or additional amount of estimated tax by reason of amendment of sections 51(a)(1)(A), (B), (2)(A) and 963(b) of this title as calling for payment of such amount or additional amount ratably on or before each of remaining installment dates for taxable year beginning with first installment date on or after the 30th day after Aug. 7, 1969; application of this section without regard to such amendment with respect to any declaration or payment of estimated tax before such first installment date; and definition of "installment date", see Pub. L. 91–53, §5(c), Aug. 7, 1969, 83 Stat. 95.