Blue Cross Blue Shield of North Carolina announced today that it turned an unexpectedly high profit in 2017, earning $734 million in net income, largely in part due to a profitable line of business in its Affordable Care Act (ACA) plans. In 2016, the company turned an overall profit, but experienced a small loss on its ACA business.

Normally, insurer profitability would suggest market stability, which suggests premiums should stabilize. But under the Trump presidency, that’s not so clear.

When insurers develop their premiums for future years, they’re trying to predict the future – how many people will we cover? How old and how sick will our members be? How much care will they need? How expensive will that care be?

With a Trump administration and Congress still hell-bent on sabotaging the Affordable Care Act, answering those questions is harder than usual. This year, Blue Cross raised its premiums by 14.1 percent, but it has repeatedly noted the fact that the price increase would have been “near zero” if not for Trump eliminating payments for cost-sharing reductions.

In December, Congress eliminated the penalty for individuals going uninsured starting in 2019. Will fewer young and healthy people enroll in future years as a result? Perhaps even more damaging, the Trump administration has proposed to make it easier to sell junk insurance plans that don’t cover critical benefits and that even charge people higher prices for pre-existing conditions. If enacted, will those new plans pull out healthy people from the ACA’s marketplaces, leaving a sicker—and more expensive—risk pool? Some policy experts think millions may leave the ACA marketplaces to flock to these low-cost, bare-bones coverage policies.

What’s best for consumers under the ACA is a stable, robust health insurance market with a broad risk pool to balance out costs. That ensures that people with chronic conditions or those who become sick don’t have to pay an arm and a leg just to have coverage.

Clearly, the ACA is working for hundreds of thousands of North Carolinians, and the market had been on a stabilizing trajectory before Trump got into office. Imagine how much more affordable health insurance could be if Congress and the President did anything but try to sabotage it.