Code of Federal Regulations CFR

As New Deal agencies issued a flood of rules in the early 1930s, there was no reliable place to find them, a problem dramatized when the government discovered in a 1935 Supreme Court case that it was prosecuting a violation of a regulation that had been revoked. Congress responded with the Federal Register Act of 1935, which created the daily Federal Register, first published on March 14, 1936, and a 1937 amendment required a codification of all rules in force, published as the Code of Federal Regulations beginning in 1938.

The CFR arranges rules by subject into 50 titles, such as Title 21 for food and drugs, Title 26 for internal revenue, and Title 40 for environmental protection, each divided into chapters by agency and then into parts and sections. A citation such as 40 CFR 50 refers to title 40, part 50. The printed CFR is revised once a year in four staggered batches, while the electronic eCFR is updated daily. It is published jointly by the Office of the Federal Register, part of the National Archives, and the Government Publishing Office.

The CFR has grown to roughly 180,000 pages, and its size is often cited in debates over the burden of federal regulation. In 2025 an executive order directed agencies to repeal at least 10 existing regulations for each new one, and the administration promoted the elimination of rules as a measure of success. Supporters of deregulation say the code is too vast and costly for businesses and citizens to follow, while defenders of regulation say page counts are a poor measure and that many rules protect health, safety, and markets.