“You could have eight or nine of 11 different views of the courts,” said William Buzbee, a professor at Georgetown Law.

A court in one circuit could issue a nationwide injunction to enforce its interpretation while another circuit disagrees, said Maura Monaghan, a partner at Debevoise & Plimpton. Few cases are taken up by the U.S. Supreme Court, which could leave clashing directives in place for many years.

In the immediate future, health policy leaders say agencies should brace for more litigation over controversial initiatives. A requirement that most Affordable Care Act health plans cover preventive services, for example, is already being litigated. Multiple challenges to the mandate could mean different coverage requirements for preventive care depending on where a consumer lives.

Drugmakers have sued to try to stop the Biden administration from implementing a federal law that forces makers of the most expensive drugs to negotiate prices with Medicare — a key cog in President Joe Biden’s effort to lower drug prices and control health care costs.

Parts of the health care industry may take on reimbursement rates for doctors that are set by the Centers for Medicare & Medicaid Services because those specific rates aren’t written into law. The agency issues rules updating payment rates in Medicare, a health insurance program for people 65 or older and younger people with disabilities. Groups representing doctors and hospitals regularly flock to Washington, D.C., to lobby against trims to their payment rates.

And providers, including those backed by deep-pocketed investors, have sued to block federal surprise-billing legislation. The No Surprises Act, which passed in 2020 and took effect for most people in 2022, aims to protect patients from unexpected, out-of-network medical bills, especially in emergencies. The high court’s ruling is expected to spur more litigation over its implementation.

“This really is going to create a tectonic change in the administrative regulatory landscape,” Twinamatsiko said. “The approach since 1984 has created stability. When the FDA or CDC adopt regulations, they know those regulations will be respected. That has been taken back.”

Industry groups, including the American Hospital Association and AHIP, an insurers’ trade group, declined to comment.

Agencies such as the FDA that take advantage of their regulatory authority to make specific decisions, such as the granting of exclusive marketing rights upon approval of a drug, will be vulnerable. The reason: Many of their decisions require discretion as opposed to being explicitly defined by federal law, said Joseph Ross, a professor of medicine and public health at Yale School of Medicine.

“The legislation that guides much of the work in the health space, such as FDA and CMS, is not prescriptive,” he said.

In fact, FDA Commissioner Robert Califf said in an episode of the “Healthcare Unfiltered” podcast last year that he was “very worried” about the disruption from judges overruling his agency’s scientific decisions.

The high court’s ruling will be especially significant for the nation’s federal health agencies because their regulations are often complex, creating the opportunity for more pitched legal battles.

Challenges that may not have succeeded in courts because of the deference to agencies could now find more favorable outcomes.

“A whole host of existing regulations could be vulnerable,” said Larry Levitt, executive vice president for health policy at KFF.

Other consequences are possible. Congress may attempt to flesh out more details when drafting legislation to avoid challenges — an approach that may increase partisan standoffs and slow down an already glacial pace in passing legislation, Levitt said.

Agencies are expected to be far more cautious in writing regulations to be sure they don’t go beyond the contours of the law.

The Supreme Court’s 6-3 decision overturned Chevron U.S.A. v. Natural Resources Defense Council, which held that courts should generally back a federal agency’s statutory interpretation as long as it was reasonable. Republicans have largely praised the new ruling as necessary for ensuring agencies don’t overstep their authority, while Democrats said in the aftermath of the decision that it amounts to a judicial power grab.

©2024 KFF Health News. Distributed by Tribune Content Agency, LLC.