Without the subsidies, insurers would probably either increase premiums or drop out entirely — but the administration, according to the report, “has refused to commit to keeping the payments going.”

Regulators fear a mass exodus by insurers from the markets — or major increases in premiums — will render the ACA coverage unattainable to many. And insurers aren’t talking — yet.

“Everybody is still in a wait-and-see mode,” Kristine Grow, a spokeswoman for the industry group America’s Health Insurance Plans, is quoted saying in the report. AHIP, along with other industry groups, is trying to win a commitment from the administration to keep making the cost-sharing payments. Grow adds, “Plans really need certainty.”

But people seeking to buy insurance aren’t the only ones who will suffer if the chaos spreads — hospitals could find themselves on the hook for care provided to those who can’t get insurance but still must seek treatment.

The irony is that some insurers were looking at a rosier financial picture before all the chaos erupted around the battle over failure to pass the AHCA, which contained provisions at once too harsh for Democrats and moderate Republicans while being far too lax to satisfy conservative Republicans.

Threats to cut the subsidies and political uncertainties about major changes to the law are threatening what otherwise would have been a profitable 2018, the report says, citing an S&P Global Ratings analysis of Blue Cross and Blue Shield health plans. The plans boosted rates more than 20 percent on average for this year, S&P said,

“The price increases they’ve put in as well as the network design changes, that’s going in the positive direction,” Deep Banerjee, the S&P analyst who wrote the report, is quoted saying. But he points out that the fate of the cost-sharing payments is a major uncertainty. And if the Republican ACA repeal bill changes things in 2018, “then all bets are off.”