UnitedHealth Group shares drop 16.5% after inquiry into alleged Medicare fraud

Group 1 - UnitedHealth Group is under investigation by the US Department of Justice for possible criminal Medicare fraud, leading to a significant drop in its stock price by 16.5% during early trading [1][4] - The company's stock value has halved since the beginning of the year, indicating a severe market rout [1] - CEO Andrew Witty announced his resignation for personal reasons, and the company suspended its full-year financial outlook due to higher-than-expected medical costs [2] Group 2 - Medicare is a government-run health insurance program for older and disabled individuals, while Medicare Advantage allows private insurers to provide health benefits under the Medicare program [3] - UnitedHealth has not received official notification regarding the criminal investigation and maintains the integrity of its Medicare Advantage program [3] - A civil fraud investigation into UnitedHealth's Medicare practices was previously reported, and US Senator Chuck Grassley is inquiring into the company's billing methods [4][5] Group 3 - UnitedHealth has historically thrived by leveraging its dominance in the insurance market and the growth of the Medicare sector [5]