A sign at the office building of health insurer Anthem is seen in Los Angeles, California Feb. 5, 2015. Reuters

One of the largest insurers and a major player in the individual insurance market, Anthem Inc., announced Tuesday that it will drop out from Ohio's Affordable Care Act (ACA) marketplace. This move would leave one fifth of the state's counties with no insurers selling individual marketplace plans in 2018, reports said.

Anthem's decision came after months of repeated warnings about the uncertainty over the payments that makes insurance affordable, could cause it to exit markets next year. Humana Inc. and Aetna Inc. both said they will pull out of their current health-law exchanges next year, reports said.

Read: Trump's Healthcare Bill Would Cover Only 5%, Might Increase Health Insurance

According to Anthem's statement, it said: "We will no longer offer Affordable Care Act [ACA] compliant Individual health plans through the Health Insurance Marketplace [also called the exchange] and will reduce our off-exchange plan offerings in Ohio for 2018. This means health benefits for these members will end on December 31, 2017. Soon, we'll send our Individual members an email sharing this news [those who've opted in to our email communications]. Then, in a couple of weeks, we'll begin sending impacted members a packet with more details. Members on a PPO plan will receive their packets in June. HMO members will receive theirs closer to the fall open enrollment period."

"We participated in [Obamacare] exchanges in all of our 14 states this year," CNBC reported citing an Anthem spokeswoman. "Regulations and deadlines for making the decisions regarding our participation vary by state and we intend to continue our dialog with regulators in our markets until that time," she said.

As part of the AFA, the federal government pays billions to insurers who in turn help lower-income people in the U.S. cover their out-of-pocket health care costs.

However, in the current scenario, Republican lawmakers and President Donald Trump are in the process to repeal and replace the Obamacare, but have disagreed over the details. This has created uncertainty over when insurers will have to submit plans and premium rates for 2018, Reuters reported.

Anthem's withdrawal from Ohio also raises other concerns such as the company considering to exit from other states' ACA marketplace.

"It seems this is more motivated by political and regulatory uncertainty, and it could be a sign that Anthem would exit nationally," the Washington Post reported citing Cynthia Cox, associate director for the Program for the Study of Health Reform and Private Insurance at the Kaiser Family Foundation. "If that is the case that could leave hundreds of thousands of people without any insurer option. This could be the tip of the iceberg," she said.

As the health care of the U.S. is still uncertain, in the recent months, Aetna pulled out of Virginia’s Obamacare exchange in February, leaving its participation in Obamacare this year to just four states. While Humana pulled out of Tennessee in February, Medica Inc., in May, said it would pull out from Iowa.