Direct-acting antiviral drugs have a 95% cure rate for hepatitis C, and few side effects. However, since they arrived on the market in 2014, public and private insurers have been hesitant to provide access to the medications, denying prescriptions up to 52% of the time.

Researchers at the Perelman School of Medicine recently published a study in the journal Open Forum Infectious Diseases that analyzed 9,000 prescriptions that were submitted to both public and private insurers from 2016 to 2017.

Because of high costs of the drugs—from $40,000 to $100,000—insurers averaged higher-than-expected denial rates, with private insurers ranking particularly high. According to study senior author Vincent Lo Re III, “It warrants continued attention from a public health standpoint to have more transparency about the criteria for reimbursement of these drugs and fewer restrictions, particularly in private insurance and certainly to continue the push in public insurance.”

The denial rates are not only high, but data from the study show the number to be increasing as well. Guidelines set by the American Association for the Study of Liver Diseases and Infectious Diseases Society of America outline steps to eliminate hepatitis C by 2030. “Eliminating hepatitis C in the US is a feasible goal,” Lo Re says, “but that’s going to be hard to achieve if payers are not reimbursing for the treatment.”