The Code of Federal Regulations (CFR) is the codification of the final regulations published in the Federal Register (Fed. Reg.) by agency and subject.
It does NOT contain regulatory history materials that are in the Fed. Reg. that led to the current regulations; i.e., neither the notice of proposed rulemaking (NPRM) nor the preamble to a final rule are in the CFR.
The CFR was first published in 1938 and has been published on an annual basis since 1967.
Use the CFR when looking for regulations that are currently in force.
The Fed. Reg. is instead helpful when you are trying to stay abreast of new or proposed regulations or when you already have citations to the CFR and want to start researching their history.
The CFR is available in print and online. At Tarlton, the print is located in the main reading room on the second floor.
Here are the major online versions:
Federal government:
LII at Cornell Law School: Free and searchable
HeinOnline: 1938 to present
Lexis Advance (login required): 1981 to present
Westlaw (login required): 1984 to present
Organization
The CFR is codified in a subject arrangement of fifty titles. (The organization of the CFR unfortunately does not correspond with that of the USC.) Each CFR title is divided into chapters, each of which is devoted to the regulations of a particular agency. These chapters are, in turn, divided into parts, each consisting of a body of regulations on a particular topic or agency function. These parts are further divided into sections, which are the basic units of the code.
Titles > Chapters > Parts > Sections
When citing a CFR section, the title, part, and section are all referenced, but not the chapter.
Ex: 21 C.F.R. § 358.301
Title = 21
Part = 358
Section = 301
Oftentimes you will come across references to the CFR only down to the part, rather than section, level. For example: 21 C.F.R. Part 358.
In the print version, at the beginning of each CFR part is:
If an individual section has been added to or amended more recently than the other sections in a part, a additional source note follows that individual section. (Ex: "[73 FR 74986, Dec. 10, 2008]").
Lexis and Westlaw vary on how they transpose these citations online. Lexis has a "History" section instead of an "Source" note, which may not necessarily include "Source" listed at beginning of a Part; it seems to depend whether any given section includes the "Authority" note listed at the beginning of a Part. Look at the print or pdf version of the CFR to understand the different citations.
Currency
The most up to date version of the CFR is the government's e-CFR, which is usually only a day or two behind.
Lexis and Westlaw are usually updated within a week or two. Westlaw, unlike Lexis, provides new developments by including red flags indicating “Regulatory Action” and linking to Fed. Reg. documents the same day they are published. On Westlaw, there are a couple of options for keeping current. One option is to click the link for Regulations, and you will see "Regulation Tracking" over on the right. Another is to create a WestClip alert (for some reason the Federal Register is only listed under "Federal Materials", not "All Content.")
The print version of the CFR is revised and reissued on a quarterly basis. Titles 1-16 contain regulations in force as of January 1 of the cover year; titles 17-27 as of April 1; titles 28-41 as of July 1; and titles 42-50 as of October 1.
The LII at Cornell Law School, the e-CFR and the online version of the CFR provided by FDSys have the advantage of being free. FDSys and the LII at Cornell Law School offer the ability to search within the CFR, but they do not offer as sophisticated online search options as Lexis and Westlaw. The two main differences between Lexis and Westlaw is that Westlaw has an index for subject searching and its CFR might have better annotations. (There is an expanded index by West, but no annotated print CFR.) It is important to be current in your research and given that the e-CFR is most up to date, it can be a good idea to double check a regulation's text there.