Wisconsin Supreme Court Ends Required Deference to State Administrative Agencies’ Interpretations, Allowing Employers to Push for Broader Review of Agency Decisions

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.