The offical U.S. Code is published every six years. There are annual supplements that represent the cumulative changes over the previous year. Even still, however, this process lags considerably behind the commercial publishers.
The third-party commercial publishers (U.S.C.A. & U.S.C.S.) are also updated with annual bound volumes. In contrast, however, they are also updated with monthly, or quarterly, pocket parts. USCCAN is also updated monthly.
The online versions of the annotated codes are updated to include session laws not included in the latest pocket part. Slip laws are also available in WestLaw (US-PL) during the week before they are organized into the Code.
The United States Code Classification Tables is a valuable resource published by the U.S House of Representatives. These tables show where recently enacted laws will appear in the United States Code and which sections of the Code have been amended by those laws. The tables sorted in Public Law order may be used to identify the sections of the Code affected by a particular law. The tables sorted in Code order may be used to determine whether a particular section of the Code has recently been amended. The tables only include those provisions of law that have been classified to the Code. The text of recently enacted laws may be found through the Library of Congress Thomas web site.