Until the court issues its ruling, there’s no way to know the exact end date for the subsidies, which the Treasury sends directly to insurance companies on behalf of Obamacare customers every month. The subsidies could be halted immediately — or not — for months, though that’s considered far less likely. The payments would not stop at all if the court rules in favor of the Obama administration.

But several lawyers consulted by POLITICO, some of whom requested anonymity because they are working on the case in some fashion, expect the tax credits to end immediately, much faster than the 25 days it takes for the official ruling to be finalized and the order formally issued.

“It would be quite some time until there was an injunction in place requiring them to act. But I would be surprised if it came to that,” said Edward A. Hartnett, an author of Supreme Court Practice, a guidebook to the court’s rules, and a law professor at Seton Hall University. “They would heed a ruling well before anyone needed to get an injunction.”