The Centers for Medicare and Medicaid Services projects 19 counties in the U.S. will have no insurers offering Affordable Care Act plans in 2018.

The agency released a map showing a concentration of those counties in Nevada, with four in Indiana and one in Ohio. CMS also projected that 1,352 counties, more than 40% of the U.S., could have only one insurer in 2018, representing more than 2.3 million exchange participants that will only have one choice.

Currently for 2018, at least 13,008 Americans currently enrolled for health coverage on the exchanges live in the counties projected to be without coverage in 2018.

On Aug. 1, CMS posted preliminary rate change requests for the 2018 coverage year which showed insurers in several states that requested rate increases of 30%.

All final rate changes for all states will be published no later than Nov. 1.