Shortly after the D.C. Circuit ruled that subsidies are illegal in 36 states in Halbig v. Burwell, the Fourth Circuit upheld he same subsidies in a related case called King v. Burwell.
That makes it sound like the case for Supreme Court review is ironclad. Not so fast.
The federal government has already stated that it's going to request "en banc" review of the Halbig decision. If the D.C. Circuit court grants that request, that would mean all eleven judges would review the ruling issued by the panel of 3 judges drawn for the case.
The D.C. Circuit as a whole skews more liberal than the panel of three judges who heard the case — there are 7 judges appointed by Democrats and only 4 appointed by Republicans — meaning there's a decent chance en banc review could reverse the decision.
The Fourth Circuit also skews liberal, so even if the plaintiffs requested en banc review in the King case, that ruling would stand.
In the end, the two rulings will likely end up consistent with each other. It is inconsistent rulings that are more likely to result review from the nation's highest court.
That said, the Supreme Court could still choose to hear the case. This new ruling just doesn't make it an inevitability.