The state is overcharging thousands of teachers, state employees and retirees for their health insurance, according to a class-action lawsuit filed against the Georgia Department of Community Health.

A. Lee Parks, one of the lawyers who filed the suit, said the state is overcharging many of the 650,000 members of the State Health Benefit Plan, which has been a political headache for Gov. Nathan Deal and DCH for almost a year.

Parks estimates that plan members have been paying more than $10 million a month in excess health insurance premiums since the agency made changes in January aimed at placating teachers, employees and retirees. Plan members had complained that the state was trying to save $200 million a year in part by charging them much higher out-of-pocket costs for health care.

The DCH changes resulted in lower out-of-pocket costs, but they left some members paying much higher rates while getting the same coverage as members paying much lower premiums.

Those paying the higher premiums still have lower deductibles for their coverage than plan members paying lower premiums, a common practice in private insurance. However, some teachers and retirees argued that they should have been allowed to sign up for the lower-cost plan once the DCH made the coverage fixes in January.

A DCH spokeswoman said the agency does not comment on pending litigation.