A professional license is a property interest, and the law that protects it is older and stranger than most licensees assume. This article explains how occupational discipline actually works — why an investigation can begin with an anonymous complaint, why a board can suspend before a hearing, and why the first written response a licensee sends is frequently the most consequential document in the case. It traces the constitutional floor from Dent v. West Virginia through Board of Regents v. Roth, Mathews v. Eldridge, and Barry v. Barchi, and explains what Withrow v. Larkin permits a board to do that would be unthinkable in a courtroom. It covers the anatomy of a board case from complaint through investigation, informal resolution, formal accusation, hearing, and judicial review, and it explains the consent order, its attractions, and the reciprocal and collateral consequences that make a quick settlement expensive years later. A worked example follows a fictional nurse through a diversion allegation, from the four-page letter she should not have written to the negotiated finding that saved her second license five years later. Sections on the parallel criminal case, the antitrust exposure of self-interested boards, the reporting databanks, and the economics of representation follow. The piece closes with the eleven mistakes that turn survivable cases into career-ending ones.