California's state-run Obamacare exchange has approved a hefty surcharge on health insurance plans and has taken other steps to help stabilize insurance companies in light of fears that certain funding from the federal government might soon dry up.

The exchange's board approved a measure that will give health insurers until Sept. 30 to add a surcharge to silver Obamacare plans. The surcharge of around 12.4 percent would help insurers if Congress or President Trump decides to not make cost-sharing reduction payments to insurers.

A major source of uncertainty for insurers is the fate of the payments, which reimburse insurers for lowering out-of-pocket costs. The Trump administration has not clarified whether these payments would continue after August.

"The lack of clarity and direction at the federal level continues to be a challenge," Peter Lee, executive director of Covered California, said Thursday.

Covered California is also changing its contract with insurers to provide some certainty if an insurer has unanticipated losses due to "changes in existing federal policies or other uncertainties, such as the lack of enforcing the individual mandate."

Under that change, an insurer could ask the state to pay for some of the losses over a three-year period, from 2019 to 2021. If an insurer earns unexpected profits due to changes in federal policies, then they will have to factor those profits into their rates over the next few years.

California is also providing an additional $5 million for marketing and outreach, for a total of $111 million. The boost comes amid criticism of the Trump administration for limiting outreach to Latinos and cutting advertising funding for Obamacare.