This chapter briefly describes several regulatory approaches to environmental policymaking. The goals of this chapter are to introduce several important analytic terms, concepts, and approaches and to describe the conceptual foundations of each approach. Specifically, this chapter discusses the following four general approaches to environmental policymaking: (1) command-and-control regulation, (2) marketbased incentives, (3) hybrid approaches, and (4) voluntary initiatives. Although command-and-control regulations have been a commonly used method of environmental regulation in the United States, the U.S. Environmental Protection Agency (USEPA) also employs the three other approaches. Market-based incentives and hybrid approaches offer the regulated community an opportunity to meet standards with increased flexibility and lower costs compared to many command-and-control regulations, while voluntary initiatives may allow environmental improvements in areas not traditionally regulated by the USEPA.