The "Sustainable Budget Act of 2025" establishes the National Commission on Fiscal Responsibility and Reform within the legislative branch. This 18-member commission, appointed by the President and congressional leadership, is charged with identifying policies to improve the nation's fiscal situation in the medium term and achieve long-term fiscal sustainability. Members must possess significant experience in government service, fiscal policy, economics, and management.

The Commission's primary duties include proposing recommendations designed to balance the budget, excluding interest payments, by the end of a 10-year period, aiming to stabilize the debt-to-GDP ratio. It must also suggest changes to meaningfully improve the long-term fiscal outlook, specifically addressing the growth of entitlement spending and the gap between projected revenues and expenditures. A final report, containing these recommendations, must be approved by at least 12 members, including a specified bipartisan representation, within one year of the Commission's formation and then submitted to Congress and made public.

Following the Commission's report, the President is required to transmit a special message to Congress within 60 days, accompanied by a proposed joint resolution to implement the Commission's recommendations. The President must consult with relevant congressional committees, the Government Accountability Office, and the Congressional Budget Office during this process. The special message must detail which recommendations were included or excluded from the proposed resolution and why, and identify programs for elimination or consolidation.

The proposed joint resolution, termed a "Commission joint resolution," is then subject to expedited consideration in both the House and Senate. This process includes strict timelines for committee action, limited debate on the floor, and crucially, prohibits any amendments to the resolution in either chamber. This ensures that the Commission's recommendations, as proposed by the President, receive a direct up-or-down vote from Congress, streamlining the legislative path for significant fiscal reforms.