Professors Monahan and Schwarcz’s recent Article in the Iowa Law Review, Rules of Medical Necessity, is a must-read for multiple audiences. In this short Response, I informally describe health insurance, and—using that perspective—describe and comment on why Rules of Medical Necessity is a piece of work that not only deserves attention from experts in the field, but is also one that casual readers should choose first when attempting to understand how health insurance works in theory and practice.