The U.S. Department of Justice has launched a civil fraud investigation into UnitedHealth Group's Medicare billing practices, as reported by The Wall Street Journal. Following the investigation report, UnitedHealth Group's shares dropped by 12 percent, resulting in a loss of over $100 per share. Physicians have alleged that UnitedHealth Group promoted misleading diagnoses through training and software, sparking concerns about the precision of medical billing. Some doctors have stated that UnitedHealth Group instructed them to record diagnoses aimed at generating profits, with some of these practices being viewed as questionable.