A court ruling out of Washington concerning the Affordable Care Act could impact millions of policyholders, including almost 1 million in Florida.

A three-judge panel of the 4th U.S. Circuit Court of Appeals unanimously ruled federal subsidies for people who enrolled in the ACA on healthcare.gov were illegal.

The decision wipes out $4.8 billion of federal subsidies, which could spike the cost of health insurance for more than 90 percent of Floridians who qualified for them.  

More than 981,00 Floridians enrolled in President Barack Obama administration's federal exchange marketplace.

The administration is expected to appeal the ruling.

Leah Barber, CEO of the health advocacy organization Florida CHAIN, said: "We are confident that when the full D.C. Court of Appeals reviews this case, they will recognize, just as other courts have ruled, that the shear intent of Congress was that marketplace enrollees who qualify for financial help will receive it."

Because the ruling on subsidies is being appealed, there will be no immediate impact for people enrolled in Florida.

The D.C. Circuit Court of Appeals ruling came on the same day a federal appeals court in Virginia upheld tax subsidies for low- and middle-income people who buy insurance under the health care reform law.