On the Internal Revenue Code (Title 26) and Statutes (8/21/17)

The following is from a current draft of the 2018 edition of my Federal Tax Procedure Books (footnotes omitted, but a link to a pdf for the footnotes is provided below (redlines show changes from the 2017 edition).
Congress enacts law.  Those laws appear in the Statutes at Large.  Those laws are commonly, but not always, presented in the U.S. Code (“U.S.C.”) which arranges laws into 54 broad “Titles” according to subject matter.  For example, the Internal Revenue Code of 1986 is Title 26.  These Titles are of two types–Titles that have been enacted by Congress (known as positive law) and Titles that have not been enacted but are editorial compilations by the House Office of Law Revision of the Statutes at Large.  Title 26 was first enacted as positive law with the 1939 Code and then again as the 1954 Code. Where the Code itself is not enacted but is instead simply a codification of statutes at large, the Code is prima facie evidence of the law but is not the law; rather the statutes at large is the law.  Where the Code is enacted as positive law (as is Title 26) and subsequently amended, the amended Code is the law.  Title 26 as amended is thus the law.  Moreover, there is law – enacted statutes – that is never codified and appears only in the Statutes at Large; in such cases, that law either does not appear in the official statutory text of the U.S.C.  but, at least sometimes, may appear in a note to a section in the official Title; care should be taken to insure that third party publishers’ versions of the Title include those notes which can be helpful. 
For readers desiring the footnotes, here is a pdf with the text and the footnotes with the redlines to show changes from the 2017 edition.

I recommend to students three Title 26 sources (actually each of these sources have all the Titles, but I link here only Title 26):

  • Office of Law Revision Title 26 here  where specific code sections can be searched and, via an outline structure, Title 26 can be viewed (this presumably is the most official; the House of Representative's Office of Law Revision Counsel offers a helpful detailed guide to the United States Code and Content here)
  • The Government Printing Office ("GPO") Title 26, here.  
  • Cornell University's LII Title 26, here.
These three Title 26 sources also offer other Titles of the U.S.C.  A helpful guide to the U.S.C. system is offered by the Office of Law Revision here.

As I mention in the excerpted quote above, Congress sometimes enacts laws that are not part of the official Code sections.  Sometimes the compilers of the Title include extra information other than the text of the enacted provisions.  This extra information is commonly referred to as statutory notes.  For example, Congress enacted special statutory relief for taxpayers who may have mischaracterized persons providing them service as independent contractors rather than employees.  The relief is in Section 530 of the Revenue Act of 1978, which is not included in the text of Title 26.  The Office of Law Revision, however, includes the entire provision of Section 530 as a note to 26 U.S.C. § 3401, here.  The note is in the GPO version here and in the LII version here (be sure and click the tab "Notes" at the top).  The notes contain other information about the statute, so in important matters it may be the better part of wisdom to check the statute and the notes.