Skip to main content

Accounting: Guide to Tax Research Documents

Resource for the study of Accounting

Federal Tax Research Documents

Tier 1

Internal Revenue Code (IRC) (legislative authority, written by the United States Congress through legislation)

Treasury regulations

Federal court opinions (judicial authority, written by courts as interpretation of legislation)

Treaties (executive authority, written in conjunction with other countries)

Tier 2

Agency interpretative regulations (executive authority, written by the Internal Revenue Service (IRS) and Department of the Treasury), including:

Final, Temporary and Proposed Regulations promulgated under IRC §7805;

Treasury Notices and Announcements;

Public Administrative Rulings (IRS Revenue Rulings, which provide informal guidance on specific questions and are binding on all taxpayers)

Tier 3

Legislative History

Private Administrative Rulings (private parties may approach the IRS directly and ask for a Private Letter Ruling on a specific issue -these rulings are binding only on the requesting taxpayer).

Tax Citations/Definitions

AFR Applicable Federal Rates
Issued as a Rev. Rul. during the last week of each month
A.O.D. Actions on Decisions
ATGs Audit Techniques Guides (formerly MSSP)
B.T.A. United States Board of Tax Appeals Reports - Official predecessor to T.C.
C.B. Cumulative Bulletin  - arranged by Code Section
C.F.R. Code of Federal Regulations
Cl. Ct. United States Claims Court Reporter
Ct. Cl. United States Court of Claims Reports
F., F.2d, F.3d Federal Reporter, 2d & 3d Series
F. Supp.
F. Supp.2d
Federal Supplement & 2d Series
Fed. Cl. Federal Claims Reporter
FR, Fed. Reg. Federal Register
G.C.M. General Counsel Memorandum
I.R.B. Internal Revenue Bulletin - Weekly
Compiled in C.B. twice a year
I.R.C. Internal Revenue Code (Title 26 of the U.S.C.)
I.R.M. Internal Revenue Manual
L. Ed., L. Ed. 2d U.S. Supreme Court Reports Lawyer's Edition & 2d Series
MSSP Market Segment Specialization Program (see ATGs)
P.L.R./L.T.R. Private Letter Rulings
Rev. Proc. Revenue Procedure, found in C.B. and I.R.B.
Rev. Rul. Revenue Ruling, found in C.B. and I.R.B.
S. Ct. Supreme Court Reporter
T.A.M. Technical Advice Memoranda, published with PLR/LTR
T.C. United States Tax Court Reports
T.C.M. Tax Court Memorandum Decisions
T.D. Treasury Decisions, in C.B., Fed. Reg., and I.R.B.
Treas. Reg. Treasury Regulations, found in C.B., Fed. Reg., and I.R.B.
U.S. United States Reports
U.S.C. United States Code
U.S.C.A. United States Code Annotated
U.S.C.S. United States Code Service
U.S.T.C. U.S. Tax Cases

IRS Publications

The Internal Revenue Service publishes an enormous amount of material that has varying levels of authority and applicability to a specific tax research question. The ones below are the IRS publications and pronouncements you are most likely to encounter.

Although not as authoritative as regulations, these materials provide important additional guidance on what taxpayers can expect the IRS to do and thus how to advise their clients.


Revenue Rulings are pronouncements about particular factual situations taxpayers have presented that the IRS determines to be of general interest. They provide analysis of a transaction and relevant Code provisions. Although they do not have the weight of regulations, they can be relied upon by a taxpayer in a similar situation. The IRS is bound by a Revenue Ruling unless it is officially revoked. Status of Revenue Rulings can be determined by using one of the citators or by checking the "Finding List of Current Action on Previously Published Rulings" in the Internal Revenue Bulletin

Revenue Procedures are IRS pronouncements about internal practice and procedure, such as describing how to request a ruling; listing requirements of how to qualify as a Subchapter S corporation; or what depreciation methods are acceptable. They are published like Revenue Rulings.

Letter Rulings. Letter rulings (LTRs) or private letter rulings (PLRs) are IRS responses to questions from individual taxpayers about proposed transactions like Revenue Rulings, but are not considered of general interest. These letter rulings are not officially published, and their application is technically limited to the taxpayer making the request and without precedential authority. They became available in 1976 under the Freedom of Information Act. They are used frequently by others as indicators of how the IRS will view a transaction and of IRS policy.

Technical Advice Memoranda (TAMs) are another type of private ruling and are issued in the same numerical series with PLRs. They are written by the IRS national office in response to a question from a field officer or taxpayer when auditing a return. Therefore, they are considering completed rather than proposed transactions. More carefully reviewed than Private Letter Rulings, they also technically have no precedential authority. Similar documents used are field service advice (FSA).

Determination Letters are responses by local IRS district offices on completed transactions.

Notices and Announcements come from the Public Affairs Division of the IRS and are used for a range of information for general distribution. Examples are to summarize a new law, or give notice of procedural changes. Both Notices and Announcements are included in the IRB, but only Notices are included in the CB.

General Counsel Memoranda or Chief Counsel's Memoranda are prepared by the IRS office of Chief Counsel as internal guidance to explain the reasoning when Revenue Rulings, Private Letter Rulings or Technical Advice Memoranda are being prepared. Since 2002, few (if any) GCMs have been issued. GCMs are numbered sequentially but without any indication of their year of issue.

Internal Revenue Manual is a compilation of operating policies and practices of the IRS. The Manual is divided into parts based on IRS department organization (e.g., Taxpayer Service, Audit, and Market Segment Specialization Program). It includes policies, procedures, instructions and guidelines related to the function and administration of the IRS. CCH publishes the Internal Revenue Manual.

Cumulative Bulletin is published by the IRS and is a compilation of the weekly IRS Bulletin and is the primary vehicle for publishing IRS pronouncements.