A new quantitative index is proposed to measure the degree to which the health care needs of a population are met. It is based on the health goals model of Lester Breslow and A. R. Somers, who listed the kinds and frequencies of health services appropriate for each of 10 developmental and maturational stages of life. The population is further divided into the sick and well segments of each of the 10 groups; the sick need treatment and the well and asymptomatic need preventive care. The index is the geometric mean of the proportions of the people in the stages whose utilization experiences conform to the services and goals appropriate for their respective group. The counting system requires the minimum information as to whether the person has received the necessary treatment for his condition if he is sick or made the requisite number of professional visits for preventive care if he is well. The index is best considered a heuristic tool for understanding a complex problem.