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Tax Research

Use this guide as an introduction to researching federal tax questions, for tax policy research and for finding IRS documents and other tax-related materials.

Findng IRS Documents: Guide

Use the links below or tabs on left menu to get a description of and how to find a specific type of IRS document.  Use the Regulations tab for Treasury Regulations and Proposed Treasury Regulations.

  • Treasury Regulations and Proposed Treasury Regulations - use Regulations tab 
  • Process for finding IRS Documents

    Process for Source gathering for IRS Documents

    1. Google - try filetype:pdf in search - see box below
    2. Identify document type – use abbreviation table
    3. If have CB or IRB citation - in pdf at HeinOnline, IRS web site or print in library
    4. Check box at left for your document type – look for pdf web site sources
    5. Look at General Resources box, below, for IRS web site links
    6. If no pdf, go to Checkpoint online or CCH Standard Federal Tax Reporter or other print resources (IRS Letter Rulings, e.g. )
    7. ASK !!

    Google Search for pdf

    Try Google search with document number and limiting by filetype:pdf - for example  rev rul 2005-31 filetype:pdf.  You can edit the document abbreviation and number to use this search box.

    Google Web Search

    General resources for finding IRS documents

    These sites have links to numerous different types of documents.  Use the drop-down menu or lnks in box at left for specific types of documents.  Sources with pdfs are noted.

    Print resources

    Print resources (most useful for older documents)

    • Cumulative Bulletin (1919-2008) [ KF6282.A2 I491 ]
    • Standard Federal Tax Reporter (back to 1945 – check Finding Devices vol.) [ KF6365.C6 ]
    • IRS Letter Rulings (for Private Letter Rulings (PLR) 1977-7/2013)  [KF6301.A4 C6]
    • IRS Positions Reporter (for GCMs) (1982- 12/2013)  [KF6300 .A83]


    Abbreviations key for frequently cited IRS (and other useful) documents (Bluebook format in italics):

    • acq or nonacq. - Notices of Acquiescence or Nonacquiescence
    • action on dec. also AOD - Actions on Decisions
    • ann - Announcements
    • CCA - Chief Counsel Advice
    • C.B. - Cumulative Bulletin
    • C.F.R. - Code of Federal Regulations
    • DO , also DLO - Delegation Order
    • FR, also Fed. Reg. - Federal Register
    • F.S.A.  -  Field Service Advice
    • Gen. Couns. Mem. also GCM - General Counsel Memoranda
    • I.R.B. - Internal Revenue Bulletin
    • I.R.C. - Internal Revenue Code: Title 26 of the United States Code
    • IRM - Internal Revenue Manual
    • NSAR - Non docketed Service Advice Review
    • Priv. Ltr. Rul. also PLR or LR - Private Letter Rulings
    • Prop. Treas. Reg. - Proposed Treasury Regulation
    • Rev. Proc. - Revenue Procedures
    • Rev. Rul. - Revenue Rulings
    • Stat. - Statutes at Large
    • T.D. - Treasury Decision (regulation with preamble)
    • Tech. Adv. Mem. also TAM, T.A. Memo. - Technical Advice Memoranda
    • T.C.M. - Tax Court Memorandum decisions
    • T.M.  also Tech. Mem. - Technical Memorandum (not the same as a TAM)
    • Treas. Reg. - Treasury Regulations: Title 26 of the Code of Federal Regulations


    Much of the content of these IRS Documents subpages was adapted from NYU's Federal Tax Research guide by AnnMarie Zell.  Many thanks to AnnMarie.