As of 2023 there are 438 federal agencies in the United States government. These agencies have developed and maintain websites open for the service and education of the public. Other resources regarding federal agencies include the Unified Agenda and Government Manual (see below), which provide more information on specific agencies, their functions, authority, organization and agendas.
A great resource to research future agency actions and considerations is the Unified Agenda. The Unified Agenda was created in response to Executive Order 12866 (58 FR 51735) and the Regulatory Flexibility Act (5 U.S.C. 602) which require that agencies publish their regulatory agendas on a semiannual basis. These agendas describe what regulatory actions agencies are developing or have recently completed. Agencies of the United States Congress are not included.
The Unified Agenda (also known as the Semiannual Regulatory Agenda), published twice a year (usually in April and October) in the Federal Register (FR). It summarizes the rules and proposed rules that each Federal agency expects to issue during the next year.
An edition of the Unified Agenda containing additional regulatory information that does not appear in the Federal Register version is available online through Reginfo.gov. The version on GPO Access is identical to the version printed in the Federal Register. Please see Reginfo.gov for Regulatory Agenda information not published in the Federal Register.
Guidance on how to read and navigate the Unified Agenda can be found at How to Read the Unified Agenda | Center for Effective Government.
The United States Government Manual is a resource that cites the statute under which an agency operates and explains the agency's functions and organizational structure. It can be found online at GovInfo and accessed as a PDF. See manual here.