Cyclopedia of Congressional Budget Law
The term program is not a specifically defined term in statute, though it refers to the purpose an entity of the Federal Government seeks to fulfill at the direction of Congress. The term may be used in the name, such as the Supplemental Nutrition Assistance Program, but usually this is not the case.
A difficulty does arise when attempting to determine whether a program is new, or simply the extension of an existing program, a replacement for such program, or perhaps merely the renaming of it. This may become important in calculating the annual baseline when such distinction become important as to whether funding should be assumed to continue, since programs enacted before the enactment of the Balanced Budget Act of 1997 (Pub. L. 105-33) are treated differently than newly created programs.
GAO Glossary of Terms and Definition (September 2005)
Generally, an organized set of activities directed toward a common purpose or goal that an agency undertakes or proposes to carry out its responsibilities. Because the term has many uses in practice, it does not have a well-defined, standard meaning in the legislative process. It is used to describe an agency’s mission, functions, activities, services, projects, and processes. (See also Program, Project, or Activity.)