WATCH: Dr. Oz questions legitimacy of ACA coverage for millions of Americans

Centers for Medicare and Medicaid Services Administrator Dr. Mehmet Oz on Wednesday questioned the legitimacy of Affordable Care Act coverage for many Americans, saying that “half” of the people enrolled in the subsidized health insurance plans “filed no claims last year.”

Watch Oz’s remarks in the video player above.

More than 24 million Americans rely on the ACA for health insurance, with the battle over extending subsidies a key sticking point in negotiations between lawmakers on Capitol Hill as the government shutdown continues with no end in sight.

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“I have to ask myself — you should be as well — if I had insurance, why would I never use it?” Oz told a reporter during an announcement about drug pricing. “The concern that has been raised is that a large number of the 12 million people who had never used their insurance last year may not legitimately have the insurance, know they have the insurance, want to have the insurance.”

Oz also said that enhanced premium tax credits that have made health insurance more affordable for ACA enrollees were meant as a short-term pandemic solution and should be allowed to expire at the end of the year.

“I think we all agree that COVID has passed,” Oz said. “Therefore, COVID-era subsidies should also pass.”

His remarks go further than some of President Donald Trump’s allies have on the issue that’s divided Congress.

Democrats are demanding an extension of the tax credits, while Republican leaders say they’re willing to negotiate on the matter once the government reopens. Open enrollment for ACA plans starts Saturday.

The Associated Press contributed to this report.