Do HMOs restrict access to health care among the chronically ill?

Health Maintenance Organizations are enrolling an increasing number of people for the delivery of their health care. Observers are asking whether this trend has resulted in the underprovision of health care to vulnerable population groups. This study asks whether HMOs under-provide care to the chronically ill. We use Ronald Andersen's Behavioral Model to derive predictive expectations about the provision of hospital and physician services to the chronically ill. The results indicate that HMOs do not under-provide health care to the chronically ill, compared to traditional fee-for-service insurance arrangements. We further found that HMOs provide more physician services to those in excellent health, compared to those in fee-for-service arrangements.