Hospitals, doctors and clinics expressed frustration that they will have to wait even longer for reimbursements after hackers paralyzed the largest U.S. billing clearinghouse.

​Read More Health Insurance and Managed Care, Hospitals, Drugs (Pharmaceuticals), Cyberattacks and Hackers, Drugstores, Computers and the Internet, UnitedHealth Group Inc, Medicare, Doctors, ALPHV/BlackCat, Federal Bureau of Investigation, American Hospital Assn, Health and Human Services Department