Getting surprise medical bills is one of the many grim realities of the U.S. health-care system and one that was legal until recently. Three former CareCube employees say, however, that the company crossed the line by purposely lying to insurers and customers like Ramirez in order to charge them unnecessary payments. The employees, who requested anonymity out of fear of retribution, say CareCube management conspired to use complicated billing procedures to exploit little-known exemptions in federal law, which requires that most COVID tests be given free of cost to patients, and then charged both parties for the same test. They say customers and insurers complained of fraudulent billing practices and that upper management has been aware of the complaints, which go back more than a year. The allegations have quietly drawn attention from federal investigators, who have interviewed at least one former employee about the alleged scheme. The U.S. Attorney’s Office in Manhattan declined to comment, and neither CareCube nor any of its employees has been charged with a crime.