TALLAHASSEE, Fla. (AP) - The Florida Association of Counties says it will challenge a new Medicaid law that's expected to cost local taxpayers millions.

The association on Thursday announced it'll sue in the coming weeks. The case will be filed in state Circuit Court in Tallahassee.

The new law will require counties to pay more than $300 million in disputed billings owed to the state-federal health care program.

The counties contend they are being made to pay for mistakes by the state's electronic billing system. The law's supporters say the counties simply are trying to avoid payment.

In signing the law on March 29, Gov. Rick Scott promised steps would be taken to make sure the bills are accurate.

Counties are required to pay part of their residents' Medicaid costs.