Generally Accepted Accounting Principles Act or GAAP Act - Requires the President's budget submission to include an estimate of the deficit or surplus for the fiscal year concerned, prepared using generally accepted accounting principles.

Amends the Congressional Budget Act of 1974 to require the alternative levels of total revenues, total new budget authority, and total outlays (including related surpluses and deficits) covered by the annual Congressional Budget Office (CBO) fiscal policy report to the congressional budget committees on the upcoming fiscal year to be prepared using both cash basis accounting and generally accepted accounting principles.