Skip to Main Content

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.

Internal Revenue Bulletin and Cumulative Bulletin Description

"The authoritative instrument for the distribution of all forms of official IRS tax guidance is the Internal Revenue Bulletin (IRB), a weekly collection of these and other items of general interest to the tax professional community."  (IRS Website )

"The contents of the weekly Bulletins were consolidated semiannually into permanent, indexed, Cumulative Bulletins  through the 2008-2 edition."  (IRB 2013-32 and at end of other IRBs.)  The official name is "Internal Revenue Cumulative Bulletin".

Documents published in the CB and IRB include:

  • Actions on Decisions
  • Announcements
  • Executive Orders
  • Legislation
  • Notices
  • Proposed, temporary and final Regulations
  • Revenue Procedures
  • Revenue Rulings
  • Tax Conventions
  • Treasury Decisions (temporary and final regulations with preamble)

Sources for the Internal Revenue Bulletin (IRB) and Cumulative Bulletin (CB)