What does each publication actually contain?
The Federal Register is published every federal business day. It contains four main categories: proposed rules (notices of proposed rulemaking), final rules, notices (meeting announcements, grant availability, information collection requests, adjudicatory orders), and presidential documents (executive orders and proclamations). Each document is paginated continuously across the calendar year, so volume 89 runs from page 1 in early January to well past 100,000 by December.
The CFR is a codification. Once a final rule takes effect, the Office of the Federal Register strips away the preamble and slots the regulatory text into the right place in one of 50 titles, which are divided into chapters (usually by agency), parts, and sections. Title 26 is Treasury/IRS, Title 17 is securities and commodities, Title 40 is EPA, Title 42 is public health and Medicare. If a final rule amends an existing section, the old language disappears from the CFR entirely and only the amended version survives.
This division dates to the Federal Register Act of 1935, passed after the government discovered mid-litigation in Panama Refining Co. v. Ryan, 293 U.S. 388 (1935), that the regulation being enforced had been repealed and no one had a reliable way to know. Publication in the Federal Register now provides legal notice to persons subject to a rule.
How does a regulation move from one to the other?
Under the APA's notice-and-comment provisions, 5 U.S.C. § 553, an agency publishes a notice of proposed rulemaking in the Federal Register, takes public comment (usually 30–90 days, through regulations.gov), and then publishes a final rule in the Federal Register. The final rule includes a preamble containing the 'concise general statement of [the rule's] basis and purpose,' the agency's responses to significant comments, cost estimates, and required regulatory-impact analyses. That preamble often runs hundreds of pages for a major rule.
The final rule ends with the amendatory text: instructions such as 'Revise § 60.5375 to read as follows' or 'Add part 1041.' The Office of the Federal Register executes those instructions and the change appears in the CFR. A rule generally cannot take effect until 30 days after publication, § 553(d), though agencies invoke exceptions and sometimes set later compliance dates.
Not everything in the Federal Register ends up in the CFR. Interpretive rules, policy statements, guidance documents, agency adjudications, and notices are published but not codified. Executive orders are the exception that proves the rule: they run in the Federal Register and are compiled annually in Title 3.
Which one should you cite, and in what form?
Cite the CFR when the regulation is in force and codified, which covers most memo and brief writing. Bluebook Rule 14.2 form: 17 C.F.R. § 240.10b-5 (2023). The parenthetical year is the year of the CFR edition you consulted, not the year the rule was adopted. Do not omit it.
Cite the Federal Register when the material was never codified, when the rule is too new to appear in the CFR, when you are citing a proposal, or—critically—when you are citing the preamble. Final rule: 89 Fed. Reg. 12,345 (Feb. 27, 2024) (to be codified at 40 C.F.R. pt. 60). Proposed rule: 89 Fed. Reg. 4,567 (proposed Jan. 24, 2024) (to be codified at 12 C.F.R. pt. 1026). Note the comma in page numbers of five digits or more. Pinpoint to the specific Federal Register page for preamble discussion: 89 Fed. Reg. at 12,388.
A common practice-ready move is a parallel citation: cite the CFR section for the operative text and the Federal Register for the agency's explanation of it. Courts do this constantly.
Why can't you skip the Federal Register?
The CFR contains no reasoning. If you are challenging a rule as arbitrary and capricious under 5 U.S.C. § 706(2)(A), the analysis under Motor Vehicle Manufacturers Ass'n v. State Farm Mutual Automobile Insurance Co., 463 U.S. 29 (1983), turns on whether the agency examined the relevant data and articulated a rational connection between the facts and its choice. That articulation lives in the preamble, not the codified text. And under the Chenery principle, an agency's action stands or falls on the grounds the agency actually invoked—so counsel's post hoc rationalizations do not count.
The preamble is also where you find whether an issue was raised in comments. Issue-exhaustion doctrine and the agency's duty to respond to significant comments both depend on the comment-and-response section. If you want to know whether a party waived an argument by not raising it during the comment period, you read the Federal Register and the docket on regulations.gov.
Finally, preamble language is a leading source of interpretive argument about ambiguous regulatory text. After Loper Bright Enterprises v. Raimondo (2024) courts no longer defer to agency statutory interpretations under Chevron, but preamble reasoning still matters for reasoned-decisionmaking review and as persuasive evidence of what the regulation means.
How do you make sure the CFR text you found is current?
The printed and govinfo CFR is revised only once a year, on a staggered schedule. Titles 1–16 are current as of January 1; Titles 17–27 as of April 1; Titles 28–41 as of July 1; Titles 42–50 as of October 1. That means a Title 42 regulation you pull in September may be eleven months stale.
The traditional paper updating chain is: find the section in the annual CFR, check the monthly List of CFR Sections Affected (LSA), then check the cumulative 'CFR Parts Affected' table in the most recent daily Federal Register. Each step tells you which Federal Register pages amended your section since the last revision date.
In practice you should use the eCFR at ecfr.gov, which is updated on a rolling basis, typically within a day or two of publication, and which shows the currency date at the top of every page. Read that date. The eCFR is an editorial compilation maintained by the Office of the Federal Register and GPO; check the status note on the site before relying on it as the official text in a filing, and cite the annual CFR edition when you can.
- ecfr.gov — daily-updated CFR with point-in-time comparison and 'compare versions' tools
- federalregister.gov — searchable Federal Register 1994–present, with document timelines and docket links
- govinfo.gov — official PDFs; Federal Register from 1994, CFR annual editions from 1996
- regulations.gov — rulemaking dockets, public comments, and supporting studies
- HeinOnline — scanned Federal Register back to 1936 and CFR back to 1938, essential for historical versions
What are the traps that catch students?
Citing the current CFR for conduct that occurred years ago. Regulatory liability is measured by the version in force at the time. Pull the annual CFR edition for that year from govinfo or Hein, and cite it with that year in the parenthetical.
Assuming a published final rule is in effect. Check the EFFECTIVE DATE and COMPLIANCE DATE fields at the top of the Federal Register document. They are frequently different, and rules are sometimes delayed, stayed by a court, or disapproved by Congress under the Congressional Review Act.
Treating a proposed rule as law. A notice of proposed rulemaking has no legal effect whatsoever. Always check the document type header.
Missing incorporated standards. Some CFR sections incorporate outside technical standards by reference under 1 C.F.R. part 51; the binding text is not in the CFR at all.
Ignoring uncodified guidance. Interpretive rules and policy statements are exempt from notice-and-comment under § 553(b), see Perez v. Mortgage Bankers Ass'n, 575 U.S. 92 (2015), so they appear in the Federal Register or on an agency website but never in the CFR—and they may drive how the agency actually behaves.