The Department of the Treasury is the executive department of the federal government responsible for implementing tax laws.

The Internal Revenue Service (the IRS), a bureau of the Treasury, issues numerous document types to both interpret the Internal Revenue Code (the "IRC") and enforce tax laws.

Treasury Regulations are the highest administrative authority issued by the Treasury Department.

• Tax regulations are codified in Title 26 of the Code of Federal Regulations (CFR), and are found in many areas of the code.

• Legislative regulations have specific language granting authority to the IRS.  These regulations are authoritative and difficult to challenge.

• Interpretative regulations are issued under the Treasury Department's general authority to make rules and regulations. They might be challenged as being contrary to the IRC or exceeding the Treasury's authority.

"Notice and Comment Practice," as required by the Administrative Procedures Act is followed in adopting regulations.  Stages used for tax are:

• Proposed regulations are issued as a "Notice of Proposed Rule Making." The IRS may publish an "Advanced Notice of Proposed Rulemaking," to receive input before a proposed regulation is drafted.  "Regulation Identification Numbers (RIFs)" and Project Numbers help track future actions.

• Temporary regulations are effective immediately. They are often issued after new IRC sections become law so that taxpayers receive guidance before the comment and revision process begins.  Temporary regulations may be in effect for up to three years and are generally required to be issued at the same time as proposed regulations.

• Final regulations have preambles containing analysis and summaries of comments, which provide background and history for interpretation. Following a mandatory comment period, the final regulation, an amended version of the proposed regulation, is adopted by a Treasury Decision (T.D.)  T.D. numbers are used for access of finding lists and citators.