Code of Federal Regulations
The codified compilation of every general and permanent rule issued by federal agencies.
What it is
The Code of Federal Regulations (CFR) 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.
Plain-English explanation
When Congress passes a statute, it goes in the U.S. Code. When a federal agency writes a rule under the authority of that statute, it goes in the CFR. The agency rules are often where the day-to-day compliance obligations actually live, the statute says ‘the Secretary shall promulgate regulations,’ the CFR has the regulations.
Each title of the CFR covers a different domain: Title 29 is Labor (including OSHA), Title 49 is Transportation, Title 40 is Environment, Title 21 is Food and Drugs. Each title is on its own annual revision cycle. Between revisions, the official CFR is not current, to know what a rule actually says today, you have to combine the most recent codified version with every Federal Register amendment since.
Why it matters
The CFR is the source of truth for federal regulatory compliance. Every audit, every inspection, every citation traces back to a specific paragraph of a specific section of the CFR. Knowing how to find, read, and cite the CFR correctly is a foundational skill for compliance work.