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Federal Tax Research: Basic Resources

Online and print resources to research federal tax.
Hierarchy of Authority for IRS Guidance and Other

Text description of the hierarchy of authority for IRS guidance in the image. A pyramid showing the Internal Revenue Code (the statutes) just above and more authoritative that the IRS "guidance" category of documents. Just under the statute are the first of two levels of the pyramid considered by the IRS as guidance The first of these levels is the Treasury (tax) Regulations, which are the laws that interpret the statutes. Just less authoritative that the regulation at the center level of the pyramid and the only other level considered by the IRS as guidance are the documents contained in the Internal Revenue Bulletin as follows: Revenue Rulings, Revenue Procedures, Notices, and Announcements. These documents are are not the law, but they must be followed by the IRS. Just less authoritative than these IRS Guidance are two kinds of documents called Written Determinations as follows: Private Letter Rulings and the Technical Advice Memoranda. These are only binding on the specific taxpayer to whom they are addressed. At the lowest and least authoritative level of the pyramid are 5 categories of resources called Other IRS Publications and Information as follows: 1 Forms and Publications, 2 News Releases and Fact Sheets, 3 FAQs, 4 Online Help and Resources, and 5 Videos. These are sources of general information but should not be cited as authority for an interpretation of the law.


The Internal Revenue Service, in the executive branch of government, promulgates (announces publicly) rules by publishing them in the Federal Register. This being done, a rule becomes a regulation with the force law, and it is codified it the Code of Federal Regulations. Regulations are also accessible in some research databases. Here are links to a few access points.


A regulation is promulgated by the Internal Revenue Service and Treasury Department in the Federal Register to get the force of law. They provide guidance for new legislation or address issues that arise with respect to existing Internal Revenue Code sections. Regulations enforce and give directions on complying with a statute.

Both proposed and final regulations are published in the Federal Register, and final regulations are codified in the Code of Federal Regulations. In addition, they are printed under the heading "Treasury Decisions" (T.D.) in the Internal Revenue Bulletin .

Types of regulations

  • General: Issued under the general authority granted to the IRS to interpret the language of the Code.
  • Legislative: IRS is directed by Congress to fulfill a law-making function and to specify substantive requirements of a tax provision; not easily challenged.
  • Temporary: not subject to public hearings, and effective immediately. Provide immediate guidance and must be followed until superseded.

Access Points