On March 27, 2019, in Kisor v. Wilkie, the US Supreme Court will hear argument on an important issue in administrative agency law: whether to overrule so-called Auer deference.  Under this doctrine, when an agency's own regulations are ambiguous, a court generally must defer to the agency's interpretation.  

Critics of Auer deference, including the late Justice Scalia, have urged overturning the doctrine.  Critics complain, amongst other things, that the doctrine encourages agencies to write ambiguous regulations, knowing that the courts will defer to their interpretation--and that it gives agencies too much power, without an effective independent check by the judiciary.  

Based on the 1997 case of Auer v. Robbins, the doctrine instructs that an agency's interpretation of its own ambiguous regulation is "controlling unless plainly erroneous or inconsistent with the regulation."  This generally requires a court to defer to the agency's interpretation--even if it is not the best--so long as the interpretation is reasonable.  In the case of Auer, for example, the Court deferred to the Secretary of Labor's interpretation of the phrase "subject to" in regulations the Secretary promulgated under the Fair Labor Standards Act.  The doctrine is also known as Seminole Rock deference, based on the 1945 case of Bowles v. Seminole Rock & Sand Co, and is similar to Chevron deference, under which a court ordinarily defers to an agency's interpretation of an ambiguous statute.  

Now, in Kisor v. Wilkie, the Court will decide the continued vitality of Auer deference.  Kisor involves an interpretation by the Department of Veterans Affairs (VA) of the word "relevant," as it appears in a VA regulation concerning disability claims.  The US Court of Appeals for the Federal Circuit upheld the VA's interpretation, and the Federal Circuit declined en banc review of the decision, with three judges dissenting.  As the dissent put it, once the panel concluded that the VA was entitled to Auer deference for its interpretation of its own ambiguous regulation, the panel "unsurprisingly" found in favor of the VA.  

It remains to be seen whether the Supreme Court will continue to endorse the Auer doctrine, particularly given recent criticisms and questions about the doctrine raised by Justices Thomas, Alito, and Roberts.  A decision overturning Auer deference could make it easier for litigants to challenge agency regulatory interpretations in court and may create opportunities for challenges that did not previously exist.  It also could impact how agencies write their regulations, with an eye towards future judicial review.  And even if the Court leaves it standing, the doctrine can be circumvented in various ways.  For example, Auer deference is inapplicable when the regulation at issue is unambiguous.  Nor does the doctrine apply when the agency, in writing the regulation, has simply parroted Congress's language in the underlying statute.