To amend title XVIII of the Social Security Act to establish a full risk ACO program.

HR8129, introduced by Rep. Tenney (R-NY) on March 26, 2026, proposes to amend Title XVIII of the Social Security Act to establish a full risk ACO program. The bill is in early stage—referred to the House Ways and Means and Energy and Commerce committees. No companion bill exists in the Senate, and the single cosponsor indicates limited bipartisan momentum. However, the legislative direction aligns with the broader bipartisan trend in Medicare policy toward value-based care. The bill does not authorize any specific funding amount; it establishes a program structure that allows Medicare to contract with risk-bearing entities. Actual revenue impact for insurers depends on CMS rulemaking and provider participation rates. The mechanism is a legislative mandate that expands the market for fully-insured Medicare risk contracts. UnitedHealth Group (UNH), Humana (HUM), Centene (CNC), and CVS Health (CVS) are structurally positioned to benefit because they already operate large Medicare Advantage and value-based care businesses. The presidential actions provided—a defense production act memorandum on energy infrastructure and an executive order on psychedelic therapies for mental health—are not directly relevant to this Medicare ACO bill and do not accelerate or conflict with it. Real market data shows substantial recent outperformance in these healthcare tickers: UNH up 41.6% over 30 days to $366.77, HUM up 35.86% to $229.72, CNC up 54.91% to $49.57, and CVS up 15.55% to $80.98. The 7-day changes are also positive: UNH +3.75%, HUM +5.67%, CNC +27.33%, CVS +5.95%. This outperformance suggests the market is already pricing in favorable Medicare policy developments, including HR8129. However, the early legislative stage means the bill has a low probability of passage in its current form; much of the price move may reflect broader sector rotation into managed care or expectation of other Medicare payment rate increases. The bill's path requires committee markup, House floor vote, Senate introduction and passage, and presidential signature—a multi-year timeline in most cases.