The Internal Revenue Code (IRC) is the tax law used at the federal level by the United States government. The IRC is contained within Section 26 of the U.S. Code, and is broken down into the following topic areas:
Subtitle A - Income Taxes
Subtitle B - Estate and Gift Taxes
Subtitle C - Employment Taxes
Subtitle D - Miscellaneous Excise Taxes
Subtitle E - Alcohol, Tobacco, and Certain Other Excise Taxes
Subtitle F - Procedure and Administration
Subtitle G - The Joint Committee on Taxation
Subtitle H - Financing of Presidential Election Campaigns
Subtitle I - Trust Fund Code
Subtitle J - Coal Industry Health Benefits
Subtitle K - Group Health Plan Requirements
A few tax-related statutes are not contained within the Internal Revenue Code. For example, bankruptcy law is contained within Section 11 of the U.S. Code.
The IRC is occasionally adjusted and updated by Congress. The IRC is enforced by the Internal Revenue Service, which can impose fines and other penalties when the IRC is breached.