Rising federal debt levels and fiscal deficits drove Moody's downgrade of the U.S. long-term sovereign rating to Aa1 from Aaa in May 2025, aligning it with S&P and Fitch at the AA+/Aa1 tier and establishing stable outlooks across agencies. With debt projected to climb toward 134% of GDP by 2035 amid elevated interest costs, traders assign a 77% implied probability against further cuts by the major agencies before 2027, reflecting the absence of acute governance shocks or rating watches since late 2025. Scope's October 2025 notch reduction to AA- underscored ongoing pressures without triggering broader actions. Key near-term catalysts include debt-ceiling negotiations and fiscal year 2027 budget outcomes, which could influence agency reviews if they alter deficit trajectories. Market-implied odds embed the resilience of Treasury demand and the dollar's reserve status as buffers against additional near-term revisions.