What the Code of Federal Regulations actually is.
A 12-minute primer on the document compliance teams cite every day, written by a regulatory publisher with 30 years of experience reading it.
What the CFR is
The Code of Federal Regulations is the codified, indexed compilation of every general and permanent rule published in the Federal Register by the executive departments and agencies of the United States government. It runs to 50 titles, more than 200,000 sections, and roughly 175,000 printed pages across the full set. RegLogic publishes 104 specific CFR titles digitally, the ones compliance teams actually use.
How it's structured
The CFR's hierarchy is Title → Chapter → Subchapter → Part → Subpart → Section → Paragraph. A typical citation like § 1910.132(d)(1) parses as: Title 29 (Labor), Part 1910 (Occupational Safety and Health Standards), Section 132 (Personal Protective Equipment, General requirements), Paragraph (d) (Hazard assessment), Sub-paragraph (1) (Verification of hazard assessment).
How it relates to the Federal Register and the U.S. Code
Three documents work together. Statutes passed by Congress live in the United States Code (U.S.C.). Regulations issued by federal agencies under statutory authority live in the Code of Federal Regulations (CFR). The Federal Register is the daily publication where new regulations, proposed rules, and notices appear before they're codified into the CFR. A new final rule published in the Federal Register today amends the CFR tomorrow.
How CFR updates work
Each CFR title is on a different annual revision cycle. Title 29 (Labor) revises July 1 each year. Title 49 (Transportation) revises October 1. Title 40 (Environment) splits across multiple July 1 revisions. Between revision dates, the official CFR is not current, to know what a regulation says today, you have to combine the most recent codified version with every Federal Register rule that has amended it since. This is what 'updated nightly' actually means: tracking the gap between the official codification and the daily Federal Register.
How to cite the CFR correctly
Standard citation form: [Title] CFR § [Part].[Section]([Paragraph])([Sub-paragraph]). Example: 29 CFR § 1910.132(d)(1). The section symbol (§) is required. The space after CFR is required. Citations to a specific year of the codification add (year) at the end: 29 CFR § 1910.132 (2026).
Common mistakes when reading the CFR
Three mistakes worth flagging. First, treating the CFR as static. The CFR you read today may not be the CFR you read last week, Federal Register amendments accumulate. Second, ignoring the effective date vs the compliance date. A final rule may be effective immediately and require compliance six months later. Citing the wrong date in an audit response gets you exactly the kind of finding nobody wants. Third, treating Letters of Interpretation as if they were the regulation. They aren't, they're agency guidance. They're persuasive but not binding in the same way the regulation itself is.