The Trump administration on Friday urged the U.S. Supreme Court to reject efforts by the U.S. House and others who want the justices to move quickly to review a federal appeals court decision that struck down the Affordable Care Act's individual mandate.

The House and a coalition of 16 Democratic-led states and the District of Columbia filed separate petitions asking the justices to expedite their review of the Dec. 18 ruling by the U.S. Court of Appeals for the Fifth Circuit. The proposed schedules would allow the court, if it wanted to take up the case, to hear arguments in April or at a special sitting in May.

The Fifth Circuit's decision "poses a severe, immediate, and ongoing threat to the orderly operation of healthcare markets throughout the country, casts doubt over whether millions of individuals will continue to be able to afford vitally important care, and leaves a critical sector of the nation's economy in unacceptable limbo," House general counsel Douglas Letter told the justices. Letter is assisted by Munger, Tolles & Olson partner Donald Verrilli Jr. and Elizabeth Wydra of the Constitutional Accountability Center.

But U.S. Solicitor General Noel Francisco countered Friday in his response that the Fifth Circuit's decision did not "definitively" resolve any question of practical significance.

The appeals panel, Francisco told the justices, sent the case back to the district court to determine whether the mandate and other provisions could be severed from the law. The House's reason for speeding up proceedings, Francisco wrote, "at bottom, is that the vitality of the ACA's myriad provisions is too important to be left unresolved. But definitive resolution of that issue will be facilitated, not frustrated, by allowing the lower courts to complete their own consideration of the question."

If the high court decides to hear the House's petition, Francisco added, the justices should adopt a briefing schedule that would allow arguments in April or May.

The Supreme Court generally stops adding cases after January to the current term's argument calendar. If the high court were to agree to hear the case under its normal schedule, arguments would be held next term—as early as October—and a decision would be unlikely before the presidential election.

U.S. District Judge Reed O'Connor in December 2018 agreed with a coalition of Republican-led states challenging the ACA that the entire law was unconstitutional because Congress in 2017 reduced to zero the tax penalty for not complying with the individual mandate to have health insurance. In 2012, a 5-4 Supreme Court upheld the mandate under Congress's tax and spend powers.

O'Connor's ruling, which was stayed pending an appeal, would have ended health coverage for an estimated 20 million people, including protection for preexisting conditions, Medicaid expansion in many states, coverage for young persons up to age 26, subsidies for low-income people and a host of other wide-ranging changes.

Trump's Justice Department argued initially that only those provisions closely tied to the mandate (requirement to sell coverage to people with preexisting conditions and not to charge them more) should be struck down with the mandate. But when ACA defenders appealed, the administration said it supported the GOP challengers' argument that the entire law must fall.

In the Fifth Circuit, a divided panel largely affirmed the district court.

"The individual mandate is unconstitutional because it can no longer be read as a tax, and there is no other constitutional provision that justifies this exercise of congressional power," Judge Jennifer Walker Elrod wrote for the panel.

Judge Carolyn Deneen King dissented, writing, "The district court's opinion is textbook judicial overreach. The majority perpetuates that overreach and, in remanding, ensures that no end for this litigation is in sight."

The appeals court sent the case back to the district court for a subsequent analysis of which of the law's provisions Congress intended to be inseparable from the mandate.