As a discipline, demand-side management (DSM) has gone through two distinct stages of development since the early 1970s. It is about to enter a third and more mature phase as the electric power industry in the USA prepares for a competitive business environment. In this new environment, only DSM that makes ＇good business sense＇ will be pursued. What makes good business sense will vary from utility to utility and from region to region based on how individual utilities define and organize their future energy services business strategies. This paper outlines the evolution of DSM in the USA from its infancy in the early 1970s to the present, including some speculation on how the future may unfold.