The year 2022 is the 50th anniversary of the publication of my demand for health model in "On the Concept of Health Capital and the Demand for Health," Journal of Political Economy 80(2): 223-255, and in The Demands for Health: A Theoretical and Empirical Investigation, NBER Occasional Paper 119 New York: Columbia University Press for the NBER. To mark that occasion, this editorial focuses on the history of the model and its impacts on the field of health economics.