The Wisconsin Supreme Court recently reversed its nearly half-century practice of deferring to state administrative agencies’ interpretations of the laws the agencies are responsible for enforcing. Based on the decision in Tetra Tech EC, Inc. v. DOR,1 Wisconsin courts need now only consider the agency interpretations’ persuasive value, but give them no deference. This shift likely will permit affected parties to more substantively challenge agencies’ interpretations of law in the state court system.
Historically, Wisconsin courts have afforded an agency’s interpretation of law “great weight deference” if the following conditions were met: (1) the agency was charged by the legislature with the duty of administering the law being interpreted; (2) the interpretation of the agency is one of long-standing; (3) the agency employed its expertise or specialized knowledge in forming the interpretation; and (4) the agency’s interpretation will provide uniformity and consistency in the application of the statute. If those conditions were met, great weight deference required that Wisconsin courts defer to the agency’s interpretation so long as it was reasonable – a low burden for the agency. Because courts were required to adopt the agency’s interpretation if it was merely reasonable, courts were precluded from adopting a different interpretation, even if an alternative interpretation was more reasonable. As a practical matter, this deference requirement made it very difficult for private litigants to prevail against agencies when challenging the agencies’ interpretations of law on appeal in Wisconsin courts.
For years, some justices on the Wisconsin Supreme Court had...
