A 2023 ProPublica investigation revealed that UnitedHealthcare was using an AI tool called 'nH Predict' to automatically cut off post-acute care for Medicare Advantage patients — often denying coverage for nursing home stays that doctors said were medically necessary. A federal lawsuit alleged the algorithm had an error rate of up to 90%, yet coverage was still being denied. Elderly patients who needed continued rehab after strokes and surgeries were being discharged and sent home before doctors considered them ready. A whistleblower claimed the company knew the tool was inaccurate but kept using it because it saved money.