The Affordable Care Act took a major blow on Tuesday in a court ruling that potentially could increase the health care costs of 4.7 million people. Then, a few hours later, another court decided the opposite.

The fight boils down to a challenged Internal Revenue Service (IRS) regulation that approves subsidies for premiums in states without their own marketplaces. Neither ruling will affect Americans right away, but the uncertainty could undermine the law.

Ruling one

The U.S. Court of Appeals in D.C. decided that workers in the 36 states that opposed the law or partly declined to set up their own marketplaces would not receive federal subsidies and, therefore, their employers would be exempt from next year’s mandate requiring them to provide health insurance. Many Americans who could not afford premiums without a subsidy would then qualify for a hardship exemption, undermining the law’s intention to require health insurance for every American.

According to federal data, 9 in 10 people live in an area without a state marketplace and bought health plans through Healthcare.gov. For those individuals, if the ruling is upheld, monthly premiums could increase from an average of $69 per month to $345 per month — from less than $1,000 annually to more than $4,000.

The plaintiffs in the case argued that a section of the Affordable Care Act said that subsidies would be available only to individuals enrolled through a state-established marketplace. The other side cited what they referred to as the “obvious” context of the law, that the Affordable Care Act was meant to provide subsidies everywhere, no matter state actions.

Ruling two

Judge Andre Davis of the Fourth Circuit Court framed the debate another way.

If I ask for pizza from Pizza Hut for lunch but clarify that I would be fine with a pizza from Domino's, and I then specify that I want ham and pepperoni on my pizza from Pizza Hut, my friend who returns from Domino's with a ham and pepperoni pizza has still complied with a literal construction of my lunch order.

In other words, Pizza Hut represents state markets and Domino’s represents Healthcare.gov. Congress asked for Pizza Hut, but Domino’s works too — as long as the end product of enrolling Americans is the same.