Congressional Budget Office Transparency Act - Amends the Congressional Budget Act of 1974 to require the Director of the Congressional Budget Office (CBO), whenever an estimate of costs is prepared for any bill or resolution, to post on the CBO public website all working papers, including data, informational papers, methodologies, spreadsheets, computer programs, background data, revenue estimates, and aggregate data provided by the Joint Committee on Taxation, and any other material used to derive such cost estimate.
Prohibits the Director from being required to post on the website any proprietary information utilized by CBO obtained from a third party with whom there is an agreement not to release such information.