Characteristics of use of mental health services by 4,254 persons enrolled in the Rand Health Insurance Study were analyzed in an attempt to predict patterns of use by a general population with assigned insurance coverage. Families in the study, whose members ranged in age from birth through 62 years, were randomly assigned to one of 14 insurance plans covering a wide variety of services by all licensed provider groups. During a one-year period less than 4 percent of the enrollees visited a mental health specialist, and only 7.1 percent saw any provider for mental health care. About half of those receiving outpatient mental health care visited general medical providers only. Annual outpatient mental health expenses per enrollee were about $25 (1983 dollars). The authors compare their findings with those of other studies and discuss their implications for insurance coverage of mental health services.