Limitations and Exclusions in Two Provider Systems with Comprehensive Care

utilization of services. Rates must be adjusted frequently to compensate for errors. Most significantly, some major policies are promulgated in the health insurance market based on judgements that are backed up with only limited, if any, firm evidence. Imposition of exclusions and limitations in health insurance contracts is based on common "wisdom" or the concerns of the underwriter about abuse of benefitsm Fears of moral hazard, unexpected disease occurrences in insured population groups, or other factors lead to the imposition of limitations or exclusions creating inaccessibility and imposing undue hardship for the enrollee. Since the cost of removing these barriers is unknown, their true costs and benefits are nearly impossible to measure. This communication reports the results of a large-scale experiment, conducted over a period of four years during which the enrolled population group did not face the usual exclusions and limitations experienced in more traditional insurance programs. An attempt has been made to estimate the effects of some of these limitations using the experiences of this study population. The emphasis is on ambulatory care services which usually are less comprehensive than inpatient care in insurance contracts. Since health behavior is strongly affected by the content of insurance coverage1, these efforts are not in any way "pure" from a scientific perspective yet they shed some light on