Traders assign a 77% implied probability to no further US sovereign downgrade before 2027 primarily because Moody’s May 2025 cut to Aa1 aligned all three major agencies at one notch below AAA, each now carrying a stable outlook. This shift followed more than a decade of rising federal debt—now exceeding $39 trillion—and elevated interest costs relative to peers, yet agencies have cited the economy’s scale, dollar reserve status, and absence of near-term fiscal shocks as balancing factors. With no negative watches or fresh warnings from S&P, Fitch, or Moody’s in 2026, and debt-ceiling resolutions avoiding acute governance concerns, market-implied odds reflect a view that another notch lower remains unlikely absent a sharp deterioration in deficit trajectories or political gridlock.