The U.S. Supreme Court preserved a key element of the Affordable Care Act that helps guarantee that health insurers cover preventive care at no cost to patients.

The justices reversed a lower court’s ruling that the U.S. Preventive Services Task Force, which under the 2010 law has a major role in choosing what services will be covered, is composed of members who were not validly appointed.

The suit started in Texas, where two Christian-owned businesses and individuals argued that health insurance plans they buy shouldn’t have to cover medical tests and drugs they object to on religious grounds, such as the HIV-prevention drug PrEP. But the legal question at the heart of the Supreme Court case was whether the task force is so powerful that, under the Constitution, its members must be appointed by the president and confirmed by the Senate.

Justice Brett Kavanaugh wrote for the 6-3 majority that Health and Human Services Secretary Robert F. Kennedy Jr. can remove task force members at will and can review their recommendations before they take effect.

“The Task Force members are removable at will by the Secretary of HHS, and their recommendations are reviewable by the Secretary before they take effect,” he wrote. “So Task Force members are supervised and directed by the Secretary, who in turn answers to the President preserving the chain of command.”

The Health and Human Services secretary has always appointed task force members and ratified their recommendations, said MaryBeth Musumeci, teaching associate professor of health policy and management at George Washington University’s Milken Institute School of Public Health.

But the ruling expanded on that authority by clarifying that the secretary also could remove members and block recommendations, she said.

Given that Kennedy had recently fired all 17 original members of the Advisory Committee on Immunization Practices, another expert panel that issues health recommendations, Musumeci said “there is reason to be worried.”

The secretary has never removed access to preventive services that have been proven to help people stay healthy, nor has the secretary “sought to shape the membership of our expert panel in any way,” task force chair Dr. Michael Silverstein said in a statement emailed to USA TODAY.

“While the HHS Secretary has long had authority over the USPSTF, historically they have only acted to increase access to preventive care, occasionally going beyond the evidence to secure enhanced coverage for preventive services,” he said. “Given our shared focus on preventing cancer and chronic disease, we certainly hope that the Secretary will allow our current work to continue unimpeded, as it has thus far.”

Katherine Hempstead, senior policy officer at the Robert Wood Johnson Foundation, a health nonprofit, praised the high court’s decision because it meant that millions of Americans still have access to preventive care such as mental health screenings, cancer screenings, STI testing and important medications.

But she also called the ruling both an “ending and a beginning.”

“It’s the ending of the challenge, but now it’s the beginning of something that’s going to unfold where we’re going to see someone exercise control over this expert panel that has very strong opinions about … many aspects of medical care,” she said.

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If Kennedy plans to target the preventive services task force, it’s unclear what preventive services could be at risk, Musumeci said. But insurance companies ultimately have the final decision. Even if the secretary vetoes a new recommendation or revokes an existing one, insurance companies can still decide to cover the preventive service.

America’s Health Insurance Plans, a trade association representing health insurance companies, plans to closely monitor the legal process but affirms that the court’s ruling will not affect any existing coverage, according to an emailed statement sent to USA TODAY.

Contributing: Maureen Groppe and Bart Jansen, USA TODAY; Reuters.

Adrianna Rodriguez can be reached at adrodriguez@usatoday.com.