This bill amends the Congressional Budget and Impoundment Control Act of 1974 to enhance oversight of major legislation's financial impact. It requires the Congressional Budget Office (CBO) to conduct annual supplemental analyses for ten years following the enactment of any significant law. The primary goal is to ensure greater transparency and accountability regarding the actual financial outcomes of federal policies. Each annual analysis must include an estimate of the actual costs and changes in Federal revenues resulting from the legislation, comparing these figures against the CBO's initial projections and updating them as needed. If a discrepancy of 10 percent or more arises between actual outcomes and previous estimates for either costs or revenues, the CBO Director must submit a report to Congress explaining the reasons for such differences. This process applies to "major legislation," defined as any bill or joint resolution projected to impact mandatory spending or federal revenue by at least 0.25 percent of the current projected Gross Domestic Product.