Humana’s announcement Wednesday that it is considering raising premiums and changing or eliminating plans makes it only the latest insurer to say it might scale back involvement on the Affordable Care Act exchanges next year. Here’s the $9 billion question those insurers that remain on the ACA marketplaces ought to consider: What happens if Donald Trump is elected–and cuts off their access to ObamaCare cost-sharing subsidies?

Subsidies related to the 2010 health-care law aim to help reduce co-payments and deductibles for low-income individuals who meet certain criteria. House Republicans challenged the subsidies in court in late 2014, arguing that because the text of the Affordable Care Act does not include a specific appropriation for the subsidies, the executive branch cannot spend money Congress never disbursed.