WASHINGTON (AP) — The number of U.S. adults without health insurance is up nearly 3.5 million this year, as rising premiums and political turmoil over “Obamacare” undermine coverage gains that drove the nation’s uninsured rate to a historic low.

That finding is based on the latest installment of a major survey, released Friday. The Gallup-Sharecare Well-Being Index asks a random sample of 500 people each day whether they have health insurance.

The survey found that the uninsured rate among adults was 12.3 percent during the period from July 1-Sept. 30, an increase of 1.4 percentage points since the end of last year. The increase in the number of uninsured is more striking because it comes at a time of economic growth and low unemployment.

The annual sign-up season for subsidized private insurance plans under the Affordable Care Act starts Nov. 1, but it may not make much of a difference.

President Donald Trump has stopped federal payments that reimburse insurers for lower copays and deductibles that the Obama-era law requires them to provide to people with modest incomes.