This paper develops an endogenous growth model having a progressive income tax structure in which heterogeneous agents, who differ in terms of their rates of time preference, supply labor elastically. We analyze the dynamic adjustment to an increase in progressivity and show that the economy will converge to an equilibrium growth path with nondegenerate distributions of both income and wealth. The role of the endogeneity of labor supply is emphasized and shown to have a major impact on the nature of the transitional path, as a result of the impact of the progressive tax on agents’ work incentives. Our theoretical analysis is supplemented with, and supported by, numerical simulations, which generally match the empirical evidence rather closely. We also show that the responses of the different income groups contrast sharply from one another so that focusing on the economy‐wide average provides an incomplete picture.