"...Congressional oversight refers to oversight by the United States Congress on the Executive Branch, including the numerous U.S. federal agencies. Congressional oversight refers to the review, monitoring, and supervision of federal agencies, programs, activities, and policy implementation.[1] Congress exercises this power largely through its congressional committee system. However, oversight, which dates to the earliest days of the Republic, also occurs in a wide variety of congressional activities and contexts. These include authorization, appropriations, investigative, and legislative hearings by standing committees; specialized investigations by select committees; and reviews and studies by congressional support agencies and staff.
Congress’s oversight authority derives from its “implied” powers in the Constitution, public laws, and House and Senate rules. It is an integral part of the American system of checks and balances....
If Congress believes that an agency has drifted from its original mandate, Congress can respond in a number of ways. Congress can pass a law to overrule agency decisions, or to narrow the agency's jurisdiction. Congress can use its appropriations power to restrict the agency's funding. Congress can also narrow the agency's regulatory authority.....