The United States Department of the Treasury is the agency that implements tax laws.
The Internal Revenue Service (IRS), a bureau of the Department of the Treasury, administers and enforces the laws.
There are two types of regulations:
1) Legislative regulations are issued by the IRS based upon a specific directive from Congress. Because Congress specifically granted the IRS the authority, this type of regulation is difficult to challenge.
2) Interpretive regulations are issued under the Treasury's general authority to make rules and regulations. This type of regulation can be challenged by showing that the rule or regulation is outside the Treasury's rule making power or the rule is contrary to the Internal Revenue Code.
One helpful database is ProQuest Regulatory Insight. You can access it through the Law Library's Database page.
Current Treasury Regulations are found in Title 26 of the Code of Federal Regulations (CFR). The Law Library also has a paper copy of the CFR.
The Official CFR is accessible on the U.S. Government and Printing Office website (CFR). Both Westlaw and Lexis also have the CFR available.
The U.S. Government and Printing Office also offers the e-CFR. Although the e-CFR is unofficial, it is the most current resource for federal regulations.
"Treasury Regulations—commonly referred to as Federal tax regulations—provide the official interpretation of the IRC by the U.S. Department of the Treasury and give directions to taxpayers on how to comply with the IRC's requirements." (IRS.gov, Tax Code, Regulations, and Official Guidance.)
Treasury Regulation sections can be found in Title 26 of the Code of Federal Regulations (26 CFR). Bluebook T1, Department of the Treasury, gives advice for citing Treasury Regulations.
You can find current regulations on GovInfo and eCFR, as well as annotated versions on password-protected sites Westlaw, Lexis, and Bloomberg.
The adoption of tax regulations follows the administrative law "notice and comment" process. All types of regulations are officially published in the Federal Register.
Important: If you find a regulation in another source, make sure you verify that it is consistent with the current code before relying on it.
There are 3 stages in the process:
Proposed Regulations are available for public comment on Regulations.gov. A link to IRS proposed rulings on regulations.gov is here, and proposed rulings from the Department of the Treasury are here. IRS proposed regulations are generally published in a Notice of Proposed Rulemaking (NPRM). You can also find them in Internal Revenue Bulletins.
You can find proposed rulings in these places:
Tax Proposed & Adopted Rulings, Westlaw
Notices of Proposed Rulings, VitalLaw
Proposed Treasury Regulations, Bloomberg
Proposed Treasury Regulations with Preambles, Westlaw
Temporary Regulations are effective immediately.
Final Regulations are published with analysis of comments and changes, which can be helpful for background information and interpretation.
Tax regulations can be superseded by new regulations. Looking to historical regulations can be useful when investigating legislative history.
You can find historical regulations in these places:
Treasury Regulations on the IRS website
US Federal Agency Documents, Decisions, and Appeals on HeinOnline
GovInfo has historical regulations back to 1996
IRS Cumulative Bulletin on Westlaw
Preambles to regulations can provide context for interpreting the regulation. Preambles are printed in the Federal Register but often are not published with temporary or final regulations in the final CFR.
HeinOnline offers instructions in how to search for preambles in the Federal Register.
Westlaw publishes Proposed Treasury Regulations with Preambles.
"A Treasury Decision (TD) is a document that contains the text of a final or temporary regulation. The TD adds new text to or removes or revises text already published in the Code of Federal Regulations (CFR). It contains a preamble that explains the rule." (Internal Review Manual, 32.1.1.2.5)
You can find PDFs of Treasury Decisions on the IRS website.
