• Subchapter A [§ 1 - § 59B] - Determination of Tax Liability

• Subchapter B [§ 61 - § 291] - Computation of Taxable Income

• Subchapter C [§ 301 - § 395] - Corporate Distributions and Adjustments

• Subchapter D [§ 401 - § 436] - Deferred Compensation, Etc.

• Subchapter E [§ 441 - § 483] - Accounting Periods and Methods of Accounting

• Subchapter F [§ 501 - § 530] - Exempt Organizations

• Subchapter G [§ 531 - § 565] - Corporations Used to Avoid Income Tax on Shareholders

• Subchapter H [§ 581 - § 601] - Banking Institutions

• Subchapter I [§ 611 - § 638] - Natural Resources

• Subchapter J [§ 641 - § 692] - Estates, Trusts, Beneficiaries, and Decedents

• Subchapter K [§ 701 - § 777] - Partners and Partnerships

• Subchapter L [§ 801 - § 848] - Insurance Companies

• Subchapter M [§ 851 - § 860L] - Regulated Investment Companies and Real Estate Investment Trusts

• Subchapter N [§ 861 - § 1000] - Tax Based on Income From Sources Within or Without the United States

• Subchapter O [§ 1001 - § 1111] - Gain or Loss on Disposition of Property

• Subchapter P [§ 1201 - § 1298] - Capital Gains and Losses

• Subchapter Q [§ 1301 - § 1351] - Readjustment of Tax Between Years and Special Limitations

• Subchapter R [§ 1352 - § 1359] - Election To Determine Corporate Tax on Certain International Shipping Activities Using Per Ton Rate

• Subchapter S [§ 1361 - § 1379] - Tax Treatment of S Corporations and Their Shareholders

• Subchapter T [§ 1381 - § 1388] - Cooperatives and Their Patrons

• Subchapter U [§ 1391 - § 1397F] - Designation and Treatment of Empowerment Zones, Enterprise Communities, and Rural Development Investment Areas

• Subchapter V [§ 1398 - § 1399] - Title 11 Cases

• Subchapter W [§ 1400 - § 1400C] - Repealed]

• Subchapter X [§ 1400E - § 1400J] - Repealed]

• Subchapter Y [§ 1400L - § 1400U-3] - Repealed]

• Subchapter Z [§ 1400Z-1 - § 1400Z-2] - Opportunity Zones