Congressional Commissions: Overview and Considerations for Congress [Updated January 22, 2021] [open pdf - 1MB]
From the Summary: "Congressional advisory commissions are formal groups established to provide independent advice; to make recommendations for changes in public policy; to study or investigate a particular problem, issue, or event; or to commemorate an individual, group, or event. While no legal definition exists for what constitutes a 'congressional commission', in this report a congressional commission is defined as a multimember independent entity that (1) is established by Congress, (2) exists temporarily, (3) serves in an advisory capacity, (4) is appointed in part or whole by Members of Congress, and (5) reports to Congress. These five characteristics differentiate a congressional commission from a presidential commission, an executive branch commission, or other bodies with 'commission' in their names. Over 150 congressional commissions have been established since 1989. [...] This report provides an overview and analysis of congressional advisory commissions, information on the general statutory structure of a congressional commission, and a catalog of congressional commissions created since the 101st Congress."
CRS Report for Congress, R40076
Congressional Research Service: https://crsreports.congress.gov/