As insurers drop out of Virginia’s individual market left and right, leaving thousands of residents scrambling, one phrase continues to pop up in discussions over the future of the Affordable Care Act: cost-sharing reduction payments.

When announcing last week that it was scaling back its participation in the ACA exchanges, Optima Health’s CEO cited uncertainty over those payments. Meanwhile, Virginia’s attorney general, Mark R. Herring, has intervened in a case to save the payments.

Cost-sharing reduction payments make health plans affordable for individuals with incomes from 100 to 250 percent of the federal poverty line who may not otherwise be able to afford the premiums, deductibles, co-insurance and other costs that go along with health insurance.

Ultimately, the reductions reduce the amount that members have to pay out of pocket.

But the members do not directly receive those cost-sharing reduction payments. The insurer does, instead, as a way of compensating them for the revenue lost by charging low-income members less.

All that has been thrown into uncertainty, though, as President Donald Trump’s administration has threatened to end the payments, which about 242,000 Virginians rely on to afford their health plans.