Nevadans living in 14 of Nevada's 17 counties who want to purchase coverage on the state's Obamacare exchange won't have any insurers to choose from next year, after two insurers decided to exit the marketplace for 2018.

Anthem Blue Cross Blue Shield said Wednesday it has decided not to offer plans on the exchange in rural Nevada. The insurer cited uncertainty in "federal operations, rules and guidance, including cost-sharing reduction subsidies," and volatility in the individual market as its reasons for leaving.

Prominence Health Plan, a smaller carrier, also announced it will leave the state entirely.

Heather Korbulic, executive director of the Silver State Health Insurance Exchange, said that as a result, more than 8,000 Nevadans will lose coverage come Jan 1.

In addition to Nevada, rural parts of Missouri, Ohio and Washington also don't have any insurers participating in the exchanges next year. Iowa, meanwhile, could become the first state without a single insurer willing to sell coverage on its exchange.

Nevada Gov. Brian Sandoval, a Republican, said he told Health and Human Services Secretary Tom Price of the insurers' decisions.

"My administration is working diligently to identify solutions to ensure there is, at the very least, a safety net available to rural Nevada residents who will be left without any options for coverage in the wake of these devastating and unfortunate decisions," Sandoval said in a statement. "The reduced footprint of carriers on the exchange will leave more than 8,000 Nevadans with no coverage, and that is unacceptable."

Anthem's decision to leave Nevada's exchange comes as Senate Republicans are debating their plan to repeal and replace parts of Obamacare. GOP senators released the details of their healthcare plan last week, and Senate Majority Leader Mitch McConnell, R-Ky., pushed for a vote on the bill before the Senate left for its week-long July 4th recess.

But after several Republican senators came out against the proposal, McConnell decided to delay the vote.