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How to Trace Federal Regulations – A Research Guide

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This post is co-written by Anne Guha, who was an intern with the Law Library’s Public Services Division this spring and is now working in Public Services, and Barbara Bavis, legal reference specialist.

Our patrons at the Law Library of Congress frequently ask us for assistance in investigating the origins and statutory authority of federal rules and regulations.  And no wonder–regulations are important to understand, because they have the force and effect of law just as federal statutes do, though they are not issued by Congress.  Instead, rules and regulations are created by a federal body such as an agency, board, or commission, and explain how that body intends to carry out or administer a federal law.  In fact, these rules and regulations can often affect our everyday lives even more directly than statutes, by laying out the details of how we go about following the laws passed by Congress. This Research Guide will address the basics of how to “trace” a federal regulation, in order to not only derive its statutory authority, but also to learn more about its origins and history.

Beginning with the Code of Federal Regulations

Government Care vs. Government Neglect. Published by Keppler & Schwarzmann. 1913. Library of Congress Prints and Photographs Division,
Government Care vs. Government Neglect. Published by Keppler & Schwarzmann. 1913. Library of Congress Prints and Photographs Division,

Researchers generally begin with a rule or regulation of interest from the Code of Federal Regulations, or CFR.   The CFR is “the codification of the general and permanent rules…by the departments and agencies of the Federal Government.”  The CFR has 50 Titles, each focusing on a subject area (Agriculture, Labor, etc.), which are then broken down into Chapters (often named for the agency that issued the rules included), Subchapters, Parts, and sometimes Subparts, before coming down to individual rules or “sections.”  Some Titles are fairly brief, spanning only a single slim volume, while others can run as many as twenty volumes long.  A citation to the CFR — for example “25 CFR 531.1” — tells you first the Title of the CFR in which your rule is located (in this example, that’s Title 25), and then gives you the section number within that Title where your rule appears (here, that’s section 531.1, which is located in Part 531).

If you’ve seen the CFR in print on the shelves of a law library, you may have noticed that these softcover volumes have spines in multiple colors.  The color of the spine helps to indicate at-a-glance when the CFR volumes were printed or updated, which is done cyclically throughout the year: Titles 1-16 of the CFR are revised as of January 1; Titles 17-27 are revised as of April 1; Titles 28-41 are revised as of July 1; and Titles 42-50 are revised as of October 1.  A monthly publication called the List of CFR Sections Affected, or LSA, cumulatively “lists proposed, new, and amended Federal regulations that have been published…since the most recent revision date of a CFR title,” to provide updated information between revisions of the CFR.

You can locate federal regulations in a variety of sources, including:

Once you have located a CFR section of interest to you, you are ready to move on to the next steps.

Statutory Authority: Authority Notes

In order for a federal agency, board, or commission to issue a rule or regulation with the force and effect of law, it must derive that authority from an explicit grant of power by Congress.  Because Congress cannot be an expert on all the details of all things, it will often pass a statute that provides a general directive, then grant an administrative body or agency the “regulatory authority” to issue rules and regulations based on that law.  The regulations passed by the agency will “specify the details and requirements necessary to implement and to enforce legislation enacted by Congress.”  Sometimes Congress will require that the agency must issue regulations on a topic, and at other times it may simply grant the agency the discretion to decide whether a rule or regulation is needed.  In either case, granting regulatory authority to a federal agency takes advantage of that agency’s subject matter expertise on a particular topic or issue, and also provides a mechanism for the law to more easily adapt and respond to change, since federal regulations can often be updated more quickly than federal statutes.

If you are interested in researching the statutory authority of a regulation (for which you already have a CFR citation), you will want to start by locating the “authority note(s)” that apply to your section of interest. You can typically find an authority note at the beginning of a larger unit of the CFR, such as at the beginning of a Part (after the initial listing of the sections contained in that Part) and/or at the beginning of each Subpart.  An authority note will list the specific sections of a law passed by Congress that authorized the federal agency to promulgate the rules and regulations that follow.  It may cite the law in more than one way, by providing multiple citations to the same law in different sources.  For example, it may cite sections as they appear: in a particular named statute or Act, in a law’s Public Law, or in the pages of the Statutes at Large or the United States Code.[1]

Regulatory History: Source Notes

Federal regulations are promulgated through a process referred to as the “rulemaking process.”  During this process, federal regulations are published in two primary sources: the CFR, discussed previously, and the Federal Register.  The Federal Register is the official daily publication of the United States Government.  It is published daily Monday through Friday and “contains Presidential documents, proposed, interim, and final rules and regulations, and notices of hearings, decisions, investigations and committee meetings.[2]  Federal rules and regulations usually appear at least twice in the Federal Register – once as a proposed rule, to provide the public with notice and with an opportunity to comment on the proposed rule, and again as the final version of the rule.  Therefore, to learn more about a rule or regulation’s history and origins, researchers generally want to trace the rule back from the CFR to where it appears in the Federal Register.

To figure out where a rule or regulation was published in the Federal Register, you will want to find that rule’s “source note(s)” in the CFR.  A source note typically appears at the beginning of a larger unit of the CFR, such as a Part or Subpart, and may also appear in brackets following a particular provision.  In either case, it will generally provide you with one or more citations to the Federal Register.  A citation to the Federal Register–for example “77 FR 58945, Sept. 25, 2012”–gives you several pieces of information, including the volume number (in this example, the citation refers you to volume 77), the page number of that volume (here, page number 58945), and the date of the issue of the Federal Register where the publication of the rule appears (here, September 25th, 2012).

Once you have a citation, you can locate the Federal Register in various sources, including:

Generally speaking, the citation you will find in the source notes will lead you to that rule or regulation’s “final rule” publication.[3]  The source note citation will likely take you to the precise page in the Federal Register where your specific rule appears, which, unfortunately, will not provide you with any information about the rule’s purpose and context.  To find this information, you will want to flip back to the beginning of the final rule and find a section called the “preamble” (fair warning, for very long rules, the preamble can be located a hundred or more pages before the page on which your provision appears).  The preamble will include a summary of the rule, a statement of “the basis and purpose” of that rule, the rule’s effective date (or applicability date), the legal authority for issuing the rule, how the CFR will be amended or changed to reflect the new rule, and other essential pieces of information.  The preamble will also frequently include a great deal of background information about the rule, such as a description of the problem the rule was designed to address, an explanation of how the rule was intended to address that problem, a summary of what public commenters had to say when the rule was proposed, descriptions of any studies or analysis the agency might have done before putting the rule into place, and much more.

For many researchers, finding the final rule notice in the Federal Register is the end goal, due to the extensive information often provided here about that rule and why it was passed.   Some researchers are interested in finding the proposed rule that predated this final rule.  To do so, simply look to the “Background” section of the final rule notice to find either a Federal Register citation to, or information about the issuance date of, the proposed rule.  If, for any reason, this information is not included in the final rule notice, researchers can use the “Docket Number,” provided at the beginning of the final rule notice, to do a search for the proposed rule notice.

Depending on your research project, next steps might include contacting the office or agency who promulgated the rule for even more information.  In the final rule notice, you might notice various pieces of information such as a Regulation Identifier Number (RIN), agency or docket number, and/or document number, under which additional documents related to the rule (such as impact statements or economic analyses) may have been organized.  Some agencies will make these types of documents available to the public upon request.

For More Information

For more information about how to conduct research regarding rules and regulations using the CFR and the Federal Register, you might consider visiting these free online resources:

We hope this Research Guide is helpful as you complete your federal legislative research.  If you have any research questions, please contact us via our Ask a Librarian service.

[1] For more information on understanding federal statutes and the U.S. Code, including where you can find these sources in print and online, we suggest reviewing our previous post, “Federal Statutes: A Beginner’s Guide.”  To learn how to trace those laws, such as to begin legislative history research, we suggest next viewing our post on tracing federal legislation.

[2] For more information about the history of the Federal Register, we suggest reading the National Archives and Records Administration publication “A Brief History Commemorating the 70th Anniversary of the Publication of the First Issue of the Federal Register.”

[3] Occasionally, the citation you find in the source note leads not to the final publication of the rule, but rather to a notice that the rule has been relocated or re-codified.  This indicates that your rule used to appear at a different position in the CFR, and was moved to its current position at a later time.  Such changes to the CFR, including such moves or re-codifications, are noted in the Federal Register, and cited in the source note to allow researchers to trace it back to its original position in the CFR.  Therefore, you will need locate the rule as it originally appeared in the CFR–prior to its move or re-codification–to find the source note leading to the rule’s ‘final publication” in the Federal Register.  Simply use the information given about the rule’s move or re-codification to look up the rule in its old position in the previous year’s CFR.  You may also find helpful information about relocated rules in the LSA for that year.

Comments (7)

  1. Happy Thanksgiving! And thank you for all the great info! I’ve copied/pasted/and saved shortcuts for futrue reference!!

  2. This is a terrific source that clearly sets out a process that’s increasingly important and information that’s hard to find – thank you so much!

  3. Why no information on how to research the Federal Acquisition Regulation. I seems like an oversight.

  4. How can I find outdated CFRs? For example, I am seeking the CFRs from 1952 that related to Aliens and Nationality. Thanks

  5. This is a great resource! Thank you! Is there a resource that helps you start with a section of the US Code to find the subsequent rule that was promulgated?

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