Congressional Budget Office
The Congressional Budget Office (CBO) was established in 1974 by the title II of the Congressional Budget and Impoundment Control Act of 1974 (Pub. L. 93-344).
Its basic mission may be found in section 202(a) (CBA) which states:
It shall be the primary duty and function of the Office to provide to the Committees on the Budget of both Houses information which will assist such committees in the discharge of all matters within their jurisdictions, including (1) information with respect to the budget, appropriation bills, and other bills authorizing or providing new budget authority or tax expenditures, (2) information with respect to revenues, receipts, estimated future revenues and receipts, and changing revenue conditions, and (3) such related information as such Committees may request.
CBO also provides information for other Committees, Members of Congress generally, and their staff. While it is a support agency of Congress and the House and Senate Budget Committees have oversight responsibility of its functions, CBO is careful to preserve its reputation for honest and objective fulfillment of its primary task: the preparation of estimates of legislation to be considered by the Congress.