The Congressional Budget Office (CBO) is

Was created as a nonpartian agency by Congressional bugdet and the Impoundment control act of 1974. As part of the legislative branch, it is a federal agency that gives economic and budget information to Congress

The Congressional Budget Office (CBO), as a federal agency under the USA government control, supplies the Congress with crucial economic and financial data. It was created in 1974 and started to operate in 1975.