Taxpayers will fork over nearly $10 billion more next year to cover double-digit premium hikes for subsidized health insurance under President Barack Obama's law, according to a study being released Thursday.

The number of Americans signing up for 2017 health plans through HealthCare.gov is running slightly ahead of a year ago, even as President-elect Donald Trump and a Republican Congress prepare to dismantle the law that provides the coverage.

The first phase of the U.S. Justice Department’s lawsuit to halt Anthem Inc.’s planned takeover of rival insurer Cigna Corp. is in the hands of a federal judge after the government wrapped up its arguments Tuesday that the deal would harm competition in the national insurance market.

Republicans in Congress are so eager to repeal the federal health law that some have vowed to get a bill to President-elect Donald Trump’s desk on the day he takes the oath of office.

Echoing recommendations from the industry’s largest trade group, health insurance executives are urging Republicans to keep the individual marketplaces from collapsing while they repeal and replace the Affordable Care Act.

Hundreds of insurers selling health plans in Affordable Care Act marketplaces are being paid less than 2 percent of nearly $6 billion the government owes them for covering customers last year with unexpectedly high medical expenses.