Oct. 20 (UPI) — The percentage of American adults without health insurance rose to 12.3 percent in the third quarter, a Gallup survey released Friday indicated.

The figure is 0.6 percent higher than it was during the second quarter. The rate of uninsured American adults increased 1.4 percent since the end of 2016, meaning about 3.5 million people are now without health insurance.

The uninsured rate: is below the peak of 18 percent in the third quarter of 2013, prior to insurance access through the Affordable Care Act.

A Gallup statement suggested that the end of some insurance companies’ involvement in health care exchanges, a rise in premiums due to the lack of provider competition and uncertainty surrounding U.S. healthcare law may be contributing to the increase in the rate of uninsured American adults.

President Donald Trump canceled cost-sharing payments that subsidize insurance plans for low-income Americans on Oct. 13. He also intervened to deny waivers to certain ACA rules in Iowa and his administration missed a deadline to apply similar waivers in Oklahoma. Iowa faces a 2018 premium rate hike of 56 percent, its two senators said. Oklahoma’s health commissioner predicted a premium increase of 30 percent next year.

On Wednesday, Trump said he is opposed to a new bipartisan congressional plan to maintain subsidies for ACA healthcare exchanges.

The Gallup survey was based on over 45,000 interviews with U.S. adults aged 18 and older from July 1 to Sept. 30, conducted as part of the Gallup-Sharecare Well-Being Index. Respondents were asked if they have health care insurance.