Tax Research - Federal Guide

This guide on federal tax research explains where and how to find tax materials.

Internal Revenue Code

Title 26 of the U.S. Code contains nearly all of the federal tax laws. This title is commonly referred to as the "Internal Revenue Code" (IRC) or sometimes simply as "The Code."

The current version is the Internal Revenue Code of 1986, as amended. There have been three major enactments of the IRC: The 1939 Code, the 1954 Code, and the 1986 Code. Prior to the 1939 Code, federal tax laws were individual Revenue Acts.

Structure. The IRC is organized into subtitles, chapters, subchapters, and parts, each of which contains related provisions on a particular topic. Related sections are often cross-referenced to each other. Therefore, it is often useful to read the table of contents to the IRC or to a subchapter in order to get an overview of the structure of a topic.


A Income Taxes
B Estate & Gift Taxes
C Employment Taxes
D Misc. Excise Taxes
E Alcohol & Tobacco Excise Taxes
F Procedure & Administration
G The Joint Committee on Taxation
H Financing of Presidential Campaigns
I Trust Fund Code
J Coal Industry Health Benefits
K Group Health Plan Benefits

Commonly-Researched Subchapters of Subtitle A (Income Taxes):

A Determination of Tax Liability (sections 1 - 59B)
B Computation of Taxable Income (sections 61 - 291)
C Corporate Distributions and Adjustments (Corporate Tax) (sections 301 - 385)
J Income Tax on Estates and Trusts (sections 641 - 692)
K Partners and Partnerships (Partnership Tax) (sections 701 - 777)
S "S Corporations" (sections 1361 -1379)

Definitions. Generally, each group of related sections will have a section of definitions. In addition, section 7701 contains over 50 definitions of terms that are used throughout the IRC.

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Historical Versions

Related Research Guides

Specialized Tax Databases

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