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Title 26

Displaying title 26, up to date as of 7/20/2026. Title 26 was last amended 7/10/2026.
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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. Determination of Sources of Income   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
Determination of Sources of Income1.861-1 – 1.863-3
§ 1.861-1Income from sources within the United States.
§ 1.861-2Interest.
§ 1.861-3Dividends and income inclusions under sections 951, 951A, and 1293 and associated section 78 dividends.
§ 1.861-4Compensation for labor or personal services.
§ 1.861-5Rentals and royalties.
§ 1.861-6Sale of real property.
§ 1.861-7Sale of personal property.
§ 1.861-8Computation of taxable income from sources within the United States and from other sources and activities.
§ 1.861-8TComputation of taxable income from sources within the United States and from other sources and activities (temporary).
§ 1.861-9Allocation and apportionment of interest expense and rules for asset-based apportionment.
§ 1.861-9TAllocation and apportionment of interest expense (temporary).
§ 1.861-10Special allocations of interest expense.
§ 1.861-10TSpecial allocations of interest expense (temporary).
§ 1.861-11Special rules for allocating and apportioning interest expense of an affiliated group of corporations.
§ 1.861-11TSpecial rules for allocating and apportioning interest expense of an affiliated group of corporations (temporary).
§ 1.861-12Characterization rules and adjustments for certain assets.
§ 1.861-12TCharacterization rules and adjustments for certain assets (temporary).
§ 1.861-13Special rules for characterization of controlled foreign corporation stock.
§ 1.861-14Special rules for allocating and apportioning certain expenses (other than interest expense) of an affiliated group of corporations.
§ 1.861-14TSpecial rules for allocating and apportioning certain expenses (other than interest expense) of an affiliated group of corporations (temporary).
§ 1.861-15Income from certain aircraft or vessels first leased on or before December 28, 1980.
§ 1.861-16Income from certain craft first leased after December 28, 1980.
§ 1.861-17Allocation and apportionment of research and experimental expenditures.
§ 1.861-18Classification of, and source of gross income from, digital content transactions.
§ 1.861-19Classification of cloud transactions.
§ 1.861-20Allocation and apportionment of foreign income taxes.
§ 1.862-1Income specifically from sources without the United States.
§ 1.863-0Table of contents.
§ 1.863-0ATable of contents.
§ 1.863-1Allocation of gross income under section 863(a).
§ 1.863-2Allocation and apportionment of taxable income.
§ 1.863-3Allocation and apportionment of income from certain sales of inventory.
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