The US Supreme Court heard oral argument Wednesday in Kisor v. Wilkie, a case dealing with federal agency deference.

The question presented is “[w]hether the Supreme Court should overrule Auer v. Robbins and Bowles v. Seminole Rock & Sand Co., which direct courts to defer to an agency’s reasonable interpretation of its own ambiguous regulation.” When an agency’s regulation is ambiguous, courts will “generally accept the agency’s interpretation of that law as long as the interpretation is reasonable (and even if the court might interpret the law differently).” This is partly because agencies are generally thought to have more “expertise in the subject covered by the law than courts do.”

This case was brought by a Vietnam War veteran who filed for disability benefits due to a post-traumatic stress disorder diagnosis. The Department of Veterans Affairs agreed with the diagnosis but “refused to give him benefits dating back to 1983” because of “its interpretation of the term ‘relevant’ in one of its regulations.”

Kisor advanced several arguments, claiming that this deference is “inconsistent with the federal Administrative Procedure Act,” and noting that under that act, ambiguities in regulations are resolved by courts. Kisor also claimed that this deference raises constitutional concerns as well as concerns about the separation of powers.

On the other hand, the government acknowledged concerns with the doctrine, but stated that the doctrine should be limited instead of overruled entirely. The government also stated that the principle of stare decisis weighs “against overruling” this doctrine.