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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.

IRB Pronouncements

IRS Pronouncements are published in the Internal Revenue Bulletin. They are also accessible in some research databases. Here are links to a few access points.

Revenue Rulings

A revenue ruling is an official interpretation by the IRS of the Internal Revenue Code, related statutes, tax treaties, or regulations. It is the conclusion of the IRS on how the law is applied to a specific set of facts.

Revenue Procedures

A revenue procedure is an official statement of a procedure that affects the rights or duties of taxpayers or other members of the public under the Internal Revenue Code, related statutes, tax treaties and regulations and that should be a matter of public knowledge.


A notice is a public pronouncement that may contain guidance that involves substantive interpretations of the Internal Revenue Code or other provisions of the law. For example, notices can be used to relate what regulations will say in situations where the regulations may not be published in the immediate future.


An announcement is a public pronouncement that has only immediate or short-term value. For example, announcements can be used to summarize the law or regulations without making any substantive interpretation; to state what regulations will say when they are certain to be published in the immediate future; or to notify taxpayers of the existence of an approaching deadline.

Access Points