A citation to the Code of Federal Regulations has four parts: the title number, the abbreviation C.F.R., the section number preceded by a section symbol, and the edition year in parentheses. In Bluebook form, a rule at Title 21, Section 101.9 of the 2025 edition is written 21 C.F.R. § 101.9 (2025). That basic pattern is how to cite the Code of Federal Regulations in nearly every style; what changes between styles is punctuation, capitalization, and whether the abbreviation is spelled out.
The Four Elements Every Citation Needs
Whether you are writing a law review note, a research paper, or a policy memo, every CFR citation carries the same information.
- The title number, from 1 through 50, identifies the broad subject area. Title 7 is Agriculture; Title 21 is Food and Drugs.1eCFR. Titles
- The abbreviation is “C.F.R.” in Bluebook and APA. The CFR’s own citation regulation uses “CFR” without periods and without a section symbol, writing citations as “1 CFR 10.2.”2eCFR. 1 CFR 8.9 – Form of Citation
- The section number points to the actual rule language. In Bluebook and APA it is introduced by a section symbol (§).
- The edition year in parentheses tells the reader which annual version of the regulation you consulted.
Most citations land at the section level, because that is where regulatory text lives.3GovInfo. Code of Federal Regulations Annual Edition Parts, chapters, and titles sit above the section in the hierarchy but rarely appear in a citation on their own.
Bluebook Format
Bluebook is the dominant style in legal writing. The structure is:
Title number + C.F.R. + § + Section number + (Year)
So: 21 C.F.R. § 101.9 (2025). No italics, no underlining, and no punctuation between elements beyond the spaces and parentheses shown.
Named Regulations
If a rule is widely known by a short name, put that name at the front:
FTC Credit Practices Rule, 16 C.F.R. § 444.1 (2025)
The name is optional. Use it when the shorthand is genuinely recognizable; skip it when it would only restate what the numbers already convey.
Pinpoints, Ranges, and Short Forms
To point at a specific subdivision, append it in parentheses immediately after the section number, with no space:
20 C.F.R. § 404.1436(e) (2025)
For a range of consecutive sections, use a double section symbol and an en dash:
21 C.F.R. §§ 101.9–101.12 (2025)
Once you have given the full citation, later references can drop everything but the section number: § 101.9. If the immediately preceding citation is to the same source, use “Id.”, adding a pinpoint if you are moving to a different subdivision: Id. § 101.10.
Choosing the Right Edition Year
The year is not decoration. The CFR’s annual print edition is revised on a staggered quarterly schedule, and different titles are current as of different dates within the same year:4National Archives. About the Code of Federal Regulations
- Titles 1–16: revised as of January 1
- Titles 17–27: revised as of April 1
- Titles 28–41: revised as of July 1
- Titles 42–50: revised as of October 1
The practical effect: if you are citing Title 42 in February 2026, the most recent official annual edition may still be the one revised as of October 1, 2025. Check which edition has actually been published before writing a year into your citation; govinfo.gov hosts the official annual editions.3GovInfo. Code of Federal Regulations Annual Edition
A wrong year is one of the most common CFR citation errors. If your citation says 2024 but you are actually relying on a 2025 amendment, a reader who pulls the 2024 volume may find different language or discover the section did not yet exist.
APA, Chicago, and MLA Variants
Non-legal styles carry the same information with different formatting.
APA uses the structure: Title or Number, Volume C.F.R. § Section (Year). For example: Protection of Human Subjects, 45 C.F.R. § 46 (2025). If the regulation is available online, add the URL. In-text, cite the first element of the reference and the year: (Protection of Human Subjects, 2025). When the rule has no commonly used name, lead with the title number.
Chicago treats regulations as government documents. It spells out and italicizes Code of Federal Regulations rather than using the C.F.R. abbreviation. A footnote looks like this:
“Nutrition Labeling of Food,” Code of Federal Regulations, title 21, sec. 101.9 (2025).
A URL can follow if direct access helps the reader. Bibliography entries use the same elements with adjusted punctuation.
MLA also treats the CFR as a government document, typically beginning the works-cited entry with “United States,” naming the code, and giving the title and section numbers with the edition or year. MLA’s handling of legal materials has shifted across editions of the MLA Handbook, so check the current edition for exact punctuation. The goal is unchanged: give a reader enough information to find the exact regulation you used.
When To Cite the Federal Register Instead
Not every federal rule you encounter has been codified. Newly issued rules, proposed rules, and interim final rules appear in the Federal Register before they land in the CFR. If a rule has not yet been codified, or you want to cite it as originally issued, cite the Federal Register.
The Bluebook Federal Register format is:
Name of regulation, Volume Fed. Reg. Page (Date).
For example: Extension of Expiration Dates for 13 Body System Listings, 90 Fed. Reg. 43,911 (Sept. 11, 2025).
When the rule will eventually be codified, add a parenthetical at the end pointing to the future CFR location: (to be codified at 20 C.F.R. pt. 404, app. 1).
The eCFR Is Not the Official CFR
Most readers access regulations at ecfr.gov, which is continuously updated and often reflects amendments within days of publication in the Federal Register. It is convenient, but federal regulation itself states that the eCFR “is not an official legal edition of the CFR.”2eCFR. 1 CFR 8.9 – Form of Citation The official legal edition is the annual print publication from the Government Publishing Office.3GovInfo. Code of Federal Regulations Annual Edition
For academic and professional writing, cite the official annual edition by year without mentioning the eCFR. If you need to cite text that is more current than the latest annual edition, cite the Federal Register entry for the amendment rather than the eCFR. Legal style guides have not adopted a standardized format for citing the eCFR directly.
One last note about what stays out of your citation. When you view a CFR section, you will see “Authority” and “Source” notes below the heading. The authority note identifies the enabling statute; the source note points to the Federal Register issue where the rule was first published.5eCFR. 1 CFR Part 21 Subpart B – Citations of Authority Neither belongs in your citation. They are research aids, useful for tracing a regulation back to its statutory basis, but they never appear in the citation string itself.