In a case that various interest groups wanted to see end what is known as “Auer deference,” the Supreme Court instead affirmed the 1997 decision behind the principle but in so doing sought to place limits on government regulators.

The Auer deference means that justices at all levels should defer to government agencies’ interpretations of regulations if the regulations are ambiguous.

In a decision that saw different justices offering different opinions for their support of Auer v. Robbins, the precedent-setting case, Justice Elena Kagan, writing for the court, emphasized that in order for a government agency’s interpretation to be valid, the interpretation must be reasonable, authoritative and based on expertise.

“Auer deference retains an important role in construing agency regulations,” she wrote. “But even as we uphold it, we reinforce its limits.”

The decision sends the case of a Vietnam veteran, denied disability benefits by the Veterans Administration (VA), back for reconsideration.

James Kisor sought disability payments stretching back to the 1980s for post-traumatic stress disorder (PTSD) but was denied by the VA. He sued, and the court sided with the administration based on Auer. In her opinion, Kagan noted that the VA “assumed too fast that Auer deference should apply.”