An audit shows six North Carolina hospitals owe the state more than $2.5 million for overcharging the health plan for teachers and state employees.
Multiple media outlets report that Wayne Memorial Hospital in Goldsboro owes the most, at $1 million.
Health plan officials say the audit findings released Friday are preliminary, and 55 hospitals remain under review.
The review has so far identified 30 hospitals that properly charged the health plan, which covers more than 661,000 state employees, teachers and retirees.
The health plan began the review in March. Officials say hospitals did not properly notify them of rate increases for outpatient care.
The state attorney general's office sent letters to the six hospitals seeking refunds.