This article studies determinants of two important sets of laws regulating insurance coverage for mental health care: mandated inclusion of minimum coverage for psychotherapy, and mandated coverage for psychologist services, the so-called freedom of choice (FOC) laws. Political market models are developed and estimated to examine the passage of mandates and FOC laws among all fifty states from 1968 through 1983. Findings indicate that a number of groups influence whether these laws are passed, including psychologists and the state, which acts both in its own interests as a direct provider of services and to protect the public's interest. A state's political system and socioeconomic environment also influence the likelihood of passage of these regulations. Our findings run counter to the assumption often made by policymakers and researchers that regulations exclusively serve the interests of providers.