How the FAR Is Amended: Proposed, Interim and Final Rules

The three ways the Federal Acquisition Regulation changes, and what each one means for the date a rule starts to bind.

Most federal acquisition rules do not appear out of nowhere. They move through a small number of predictable document types, and the type tells you how much time you have before the change bites.

Proposed rules

A proposed rule is a formal notice that an agency intends to change the regulation, published in the Federal Register for public comment. It is not yet in force. The notice carries a comment-close date, usually 30 to 60 days after publication, and the text invites written comments. A proposed rule that matters to you is an opportunity: the agency has not finalised the language, and comments submitted before the deadline are placed in the rulemaking record and must be considered.

Interim rules

An interim rule takes effect immediately or on a stated date, but the agency still accepts public comment and may revise the language afterward. Interim rules are used when an agency believes it cannot wait for the full notice-and-comment cycle, often because of a statute, an executive order or an urgent national-security need. An interim rule is in force, so it can change what a current solicitation requires even while comments are open.

Final rules

A final rule is the version that is adopted. It states an effective date, which may be immediate or delayed, and it usually responds to the comments received on the earlier proposal. A final rule can also be published without a prior proposal when an agency says notice and comment would be impracticable or contrary to the public interest.

Reading the dates, not just the title

The two dates that matter are the publication date and the effective date. They are different. A rule published on one date can take effect weeks later, and a proposed rule has no effective date at all until it is finalised. The register on this site shows both fields for every entry, alongside the comment-close date where one applies, so you can see not only what changed but when it starts to bind and whether you still have a window to comment.

Why the sequence matters

Treating a proposed rule as if it were final leads to changes you did not need to make yet. Treating a final rule as if it were a proposal leads to the opposite and worse problem: you keep pricing and staffing work on a rule that has already changed. Following the document type, rather than the headline, keeps the two apart.