The Code of Federal Regulations (CFR) is the codification of the general and permanent rules and regulations (sometimes called administrative law) published in the Federal Register by the executive departments and agencies of the federal government of the United States. The CFR is divided into 50 titles that represent broad areas subject to federal regulation.

The CFR annual edition is the codification of the general and permanent rules published by the Office of the Federal Register (part of the National Archives and Records Administration) and the Government Publishing Office. In addition to this annual edition, the CFR is published in an unofficial format online on the Electronic CFR website, which is updated daily.

The Federal Register Act originally provided for a complete compilation of all existing regulations promulgated prior to the first publication of the Federal Register, but was amended in 1937 to provide a codification of all regulations every five years.[7] The first edition of the CFR was published in 1938.[7] Beginning in 1963 for some titles and for all titles in 1967, the Office of the Federal Register began publishing yearly revisions, and beginning in 1972 published revisions in staggered quarters.

On March 11, 2014, Rep. Darrell Issa introduced the Federal Register Modernization Act (H.R. 4195; 113th Congress), a bill that would revise requirements for the filing of documents with the Office of the Federal Register for inclusion in the Federal Register and for the publication of the Code of Federal Regulations to reflect the changed publication requirement in which they would be available online but would not be required to be printed. The American Association of Law Libraries (AALL) strongly opposed the bill, arguing that the bill undermines citizens’ right to be informed by making it more difficult for citizens to find their government’s regulations. According to AALL, a survey they conducted “revealed that members of the public, librarians, researchers, students, attorneys, and small business owners continue to rely on the print” version of the Federal Register. AALL also argued that the lack of print versions of the Federal Register and CFR would mean the 15 percent of Americans who don’t use the internet would lose their access to that material. The House voted on July 14, 2014 to pass the bill 386–0.

Code of Federal Regulations related to disabled Americans use of service dogs, service dogs in training and emotional support animals