The purpose of this study was to determine for a sample of Montana families if a positive relationship existed between the family's socioeconomic status and its medical initiation behavior, and then, controlling for socioeconomic status, to determine if a relationship existed between initiation of professional medical care and a number of variables that perhaps affect the decision to visit the doctor or dentist. In the latter endeavor, a model suggested by McNerney and his colleagues was used to organize the analysis of several factors that may influence the decision to initiate medical care. A stratified sample of 574 families was surveyed. Persons in the lower classes have poorer health than the more privileged. Yet, many persons with low incomes go to doctors and dentists, some as often as or more often than those with greater incomes. The hypothesis proposing a positive relationship between the ability to pay as measured by the possession of health insurance and the initiation of professional medical care is supported by the data, but only with some modifications. The general hypothesis seems to be tenable for the lower status group in the sample, but does not hold true for the higher status families. The family in the higher socioeconomic status group tends to initiate medical care at about the same rate whether it has health insurance or not. (NL)