Part of a special theme issue on Communicating Critical Test Results, this article outlines a series of safe practice recommendations, building on an initiative organized by the Massachusetts Coalition for the Prevention of Medical Errors and the Massachusetts Hospital Association. The authors provide context to their recommendations and then offer a detailed table that walks users the suggested practices. Related appendices provide rationale and operating definitions for communicating critical test results as well as a “starter set” for specific values and interpretations. A previous AHRQ WebM&M commentary addressed the issue of communication surrounding critical laboratory values.