A U.S. Senate Judiciary Committee investigation reviewed over 50,000 pages of internal UnitedHealth Group documents and concluded that the insurer deployed nurses for in-home visits, offered financial incentives to physicians, and used artificial intelligence tools to search medical records for additional diagnoses. The committee found some diagnoses lacked proper clinical confirmation and may have driven higher federal payments through the Medicare Advantage program. UnitedHealth Group has disputed characterizations of wrongdoing and maintains that its coding practices comply with Medicare rules, but the probe has intensified regulatory scrutiny and prompted calls for tighter oversight of diagnosis-driven payment models.

Following publication of the Senate report, UnitedHealth’s shares declined 2.5% on the first trading day, erasing roughly $6 billion in market capitalization. Analysts have revised their full-year Medicare Advantage risk-adjusted revenue growth outlook down by 100 basis points to mid-teens percentages, citing potential reimbursement clawbacks and increased compliance costs. Morgan Stanley and Goldman Sachs both flagged a potential 50 to 75 basis-point hit to UnitedHealth’s 2026 operating margin from enhanced audit provisions and legal reserves tied to the investigation’s findings.

UnitedHealth Group also released two independent Milliman studies estimating 2025 costs, which found Medicare Advantage plans cost the federal government 9% less per member per month than traditional Medicare—$1,117 versus $1,234—yielding over $1,400 in annual savings per enrollee. Milliman further estimated that non-dual eligible, aged-in beneficiaries in Medicare Advantage Prescription Drug plans will spend 53% less out-of-pocket in 2025—$3,651 compared with $7,790 under traditional Medicare with a standalone drug plan and Medigap coverage. The studies credit managed care structures, provider networks, and value-based arrangements for driving efficiency, and underscore UnitedHealth’s argument that risk-adjusted payments fund enhanced supplemental benefits such as dental, vision and hearing coverage.