Physicians do modeling – every day, all day. It’s just that it’s done with hideous imprecision making cross-patient conclusions hazardous and extensibility impossible. Most of these mental models are devoid of formal logic. Rather, these mental models are patterns matched in a specific patient with a specific problem(s) based on a clinician’s experience and “book-knowledge”. We will explore some of the steps that could contribute to the broader acceptance of mathematical models in health care. We will distinguish models that impact the care of the individual patient from that of a larger population.