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Title 26

Displaying title 26, up to date as of 9/09/2026. Title 26 was last amended 9/08/2026.
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  1. Title 26 —Internal Revenue
  2. Chapter I —Internal Revenue Service, Department of the Treasury
  3. Subchapter A —Income Tax
  4. Part 1 —Income Taxes
  5. Additions to the Tax, Additional Amounts, and Assessable Penalties   View Full Text
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Title 26Internal RevenuePart / Section
Chapter IInternal Revenue Service, Department of the Treasury1 – 899
Subchapter AIncome Tax1 – 18
Part 1Income Taxes1.0-1 – 1.9300-1
Additions to the Tax, Additional Amounts, and Assessable Penalties1.6654-1 – 1.6851-3
§ 1.6654-1Addition to the tax in the case of an individual.
§ 1.6654-2Exceptions to imposition of the addition to the tax in the case of individuals.
§ 1.6654-3Short taxable years of individuals.
§ 1.6654-4 [Reserved]
§ 1.6654-5Payments of estimated tax.
§ 1.6654-6Nonresident alien individuals.
§ 1.6654-7Applicability.
§ 1.6655-0Table of contents.
§ 1.6655-1Addition to the tax in the case of a corporation.
§ 1.6655-2Annualized income installment method.
§ 1.6655-2TSafe harbor for certain installments of tax due before July 1, 1987 (temporary).
§ 1.6655-3Adjusted seasonal installment method.
§ 1.6655-4Large corporations.
§ 1.6655-5Short taxable year.
§ 1.6655-6Methods of accounting.
§ 1.6655-7Addition to tax on account of excessive adjustment under section 6425.
§ 1.6655(e)-1Time and manner for making election under the Omnibus Budget Reconciliation Act of 1993.
§ 1.6662-0Table of contents.
§ 1.6662-1Overview of the accuracy-related penalty.
§ 1.6662-2Accuracy-related penalty.
§ 1.6662-3Negligence or disregard of rules or regulations.
§ 1.6662-4Substantial understatement of income tax.
§ 1.6662-5Substantial and gross valuation misstatements under chapter 1.
§ 1.6662-5TSubstantial and gross valuation misstatements under chapter 1 (temporary).
§ 1.6662-6Transactions between persons described in section 482 and net section 482 transfer price adjustments.
§ 1.6662-7Omnibus Budget Reconciliation Act of 1993 changes to the accuracy-related penalty.
§ 1.6662-9Inconsistent estate basis reporting.
§ 1.6664-0Table of contents.
§ 1.6664-1Accuracy-related and fraud penalties; definitions, effective date and special rules.
§ 1.6664-2Underpayment.
§ 1.6664-3Ordering rules for determining the total amount of penalties imposed.
§ 1.6664-4Reasonable cause and good faith exception to section 6662 penalties.
§ 1.6664-4TReasonable cause and good faith exception to section 6662 penalties.
§ 1.6694-0Table of contents.
§ 1.6694-1Section 6694 penalties applicable to tax return preparers.
§ 1.6694-2Penalty for understatement due to an unreasonable position.
§ 1.6694-3Penalty for understatement due to willful, reckless, or intentional conduct.
§ 1.6694-4Extension of period of collection when tax return preparer pays 15 percent of a penalty for understatement of taxpayer's liability and certain other procedural matters.
§ 1.6695-1Other assessable penalties with respect to the preparation of tax returns for other persons.
§ 1.6695-2Tax return preparer due diligence requirements for certain tax returns and claims.
§ 1.6696-1Claims for credit or refund by tax return preparers or appraisers.
§ 1.6709-1TPenalties with respect to mortgage credit certificates (temporary).
§ 1.6851-1Termination assessments of income tax.
§ 1.6851-2Certificates of compliance with income tax laws by departing aliens.
§ 1.6851-3Furnishing of bond to insure payment; cross reference.
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