What Is the eCFR? Is It Official, and How Do You Search It?

Short answer: The eCFR is a free website that shows the Code of Federal Regulations, the full set of rules federal agencies have issued. It updates every day. The government calls it "authoritative but unofficial," and the official copy is the yearly CFR edition on GovInfo, the federal publishing site. Use the eCFR to find and read a rule. Check the official edition before you cite it in a filing.

Written and checked on 12 October 2026. This is general information, not legal advice; check the cited statute or opinion before relying on it.

TL;DR

• The eCFR is a web copy of the CFR. The Office of the Federal Register, part of the National Archives, updates it daily.
• Three copies carry three legal weights. The yearly CFR edition is official. The eCFR is not. The daily Federal Register is where each change first appears.
• It is not real time. The eCFR says it is generally current within two business days. It leaves out temporary rules.
• To search, type the citation. Typing "1 CFR 1.1" and picking the suggestion takes you to that section.

Official text, as of 12 October 2026

The eCFR status page says the eCFR "is an editorial compilation of CFR material and amendments published in the daily Federal Register" (read on 12 October 2026). The About This Site page calls the content "authoritative but unofficial" too.

What changed in 2025 and 2026. In January 2025, Pub. L. 118-267 rewrote 44 U.S.C. 1510. Subsection (c) now lets the Office of the Federal Register "provide public access using an electronic edition that allows a user to select a specific date," much like the eCFR's date feature. The eCFR's own pages still call it unofficial.

What the eCFR is

The Code of Federal Regulations, or CFR, collects the general and permanent rules that federal agencies publish in the Federal Register. The Federal Register is the government's daily journal of new rules and notices. The CFR has 50 titles, and each title is a broad subject area. The eCFR is the web version. It is a compilation, meaning editors merge each new amendment into the existing text. A printed volume is fixed once a year.

For how the CFR relates to the statutes Congress passes, see USC versus CFR. For what a regulation is, see regulations versus statutes.

Is the eCFR official?

There are three copies of the same rules. The government gives each a different status.

Two sections of federal law show why the labels matter. Under 44 U.S.C. 1507, the "contents of the Federal Register shall be judicially noticed," which is a rule for courts. Judicial notice means a court accepts a document as genuine without proof. Section 1510(e) of the same chapter covers the CFR. It says the codified documents published there are "prima facie evidence of the text of the documents and of the fact that they are in effect on and after the date of publication" under that section. Prima facie evidence counts as correct until someone shows otherwise.

Those sentences cover the Federal Register and the published CFR. Subsection (c) now mentions an electronic edition. The prima facie sentence in (e) still covers only documents "published in the Code of Federal Regulations," and it names no website. An older National Archives page still says "e-CFR." It adds that the compilation "does not provide legal notice to the public or judicial notice to the courts" until the ACFR grants it official status. A newer Archives page calls it "unofficial but endorsed by the ACFR." The eCFR's Getting Started page says it "is not an official legal edition of the CFR." This guide did not research court rulings, so it makes no claim about how courts treat the eCFR.

How current is it?

The eCFR is updated daily but not in real time. It says "generally the eCFR is current within two business days." On 12 October 2026 its own title list showed Title 45 current through 8 October 2026. Check the date at the top of the page.

A new rule names an effective date, the day it starts to apply. The eCFR says amendments are typically available about two business days after their effective date. Agencies "may correct, delay, or withdraw amendments before the effective date," so it tells readers to check the day after a rule is due to take effect.

Some rules never appear. Like the yearly editions, the eCFR does not include or link to "temporary rules" or other rules "in effect for less than one year." It also leaves out waivers and most policy statements. They live in the daily Federal Register and the List of CFR Sections Affected, a government index of CFR sections that changed.

The eCFR shows the code "at points in time back to January 2017." For earlier dates, use the yearly editions. The National Archives says all titles are on GovInfo from 1997. Titles 42 to 50, which include Title 45, are fixed as of October 1. On 12 October 2026 GovInfo had no 2026 edition of Title 45 at its usual file address. The newest official one was from 2025. Our post on CFR annual editions and point-in-time lookups covers dates in more depth.

One regulation, read from top to bottom

Take a data breach at a health care company. The rule is 45 CFR 164.404, "Notification to individuals."

Read the address first. Title 45 is Public Welfare. The section sits in Part 164 (Security and Privacy), Subpart D. That subpart covers notice after a breach of unsecured protected health information. A "covered entity" is the rule's term for the groups it covers. Paragraph (b) says it "shall provide the notification required by paragraph (a) of this section without unreasonable delay and in no case later than 60 calendar days after discovery of a breach," with one exception. A law-enforcement delay under 164.412 can pause the clock.

Then find two lines. The Authority line lists the statutes behind the rule. For Part 164 it begins "42 U.S.C. 1302(a); 42 U.S.C. 1320d-1320d-9." The Source line names the Federal Register page that created the rule. For Subpart D it reads "74 FR 42767, Aug. 24, 2009." The notice there is titled "Breach Notification for Unsecured Protected Health Information." It took effect on 23 September 2009.

Now check the official copy. The 2025 yearly edition of this section on GovInfo, headed "45 CFR Subtitle A (10-1-25 Edition)," has the same 60-day wording as the eCFR. One trap: the eCFR's change history for this section starts on 30 December 2016, long after the rule was written. That date marks where the eCFR's own records begin.

How to search the eCFR

The eCFR's help pages describe these steps.

1. Type a citation into the search box, such as "1 CFR 1.1," "Part 1234" or "Title 7 Chapter III." Pick the matching suggestion to jump there.
2. Type words from a heading, such as "Regulation Z." Suggestions come from headings only, and the words must match in order.
3. Press return for full-text search. Searches are stemmed, so "fishes" also finds "fish." Put a phrase in quotes. Use a minus sign to exclude a word.
4. Use the date field to search the code as it stood on an earlier day, back to January 2017.
5. Browse by agency to see which titles and chapters hold an agency's rules.

What each title covers

The eCFR lists 50 title numbers, but Title 35 is marked "Reserved," so 49 hold content.

What goes wrong

• Citing the eCFR page in a filing. Cite the yearly edition and say which year.
• Reading the top date as "today." It can be days old.
• Missing a short-lived rule. An emergency rule in force for six months is not in the eCFR.
• Expecting a rule that took effect today to show today. It can take two business days.
• Using a title's "last amended" date for one section. That date covers the whole title.

For the US statutes, regulations and court rules these laws sit in, see the US primary law API.

This guide is part of US Law Data: The Complete Guide, a map of where US law comes from and how to use it.

FAQ

What does eCFR stand for, and is it the same as the CFR?

It stands for Electronic Code of Federal Regulations. It is a web copy of the CFR plus the amendments published since. The official CFR is the yearly edition. Developers who want the data as a feed can read our guide to the eCFR API and bulk data.

Is the eCFR official or legally binding? Is the Code of Federal Regulations law?

The government calls the eCFR "authoritative but unofficial" and an information source. The rules are federal agency rules, issued under power Congress gave the agency. Each part lists its statutes. The web copy has no separate status, so check the yearly edition and the Federal Register for anything important. Under 44 U.S.C. 1510(e), the published CFR is prima facie evidence of a rule's text and that it is in effect.

How often is the eCFR updated?

Daily, though not in real time. The Office of the Federal Register says it is generally current within two business days.

How do I find a regulation in the eCFR?

Type its citation, such as "49 CFR 172.101," into the search box. If you only know the subject, try words from a heading or browse by agency. How to cite a statute or regulation explains the citation form.

Can I see an old version of a rule?

On the eCFR, yes, back to January 2017. For earlier dates, use the yearly editions on GovInfo.

What is Title 49, Title 21 or Title 29 of the CFR?

The eCFR names Title 49 Transportation, Title 21 Food and Drugs, and Title 29 Labor. Agencies that regulate a subject usually have chapters inside its title.

Priyansh Khodiyar

Co-Founder & CTO

Priyansh leads engineering and AI at Vaquill AI: the pipelines that pull statutes, regulations and court rules from every US jurisdiction's official publisher, and the REST API, MCP server and open dataset that serve them.