The author has brought together in this book a great mass of factual data. Medical care insurance is defined as a device for pooling risks and resources against the economic hazards of sickness, injury and maternity. Pooling of risks is feasible only for people able to make regular contributions; even under optimum conditions of employment and income there is a segment of the population who have to depend upon public aid for maintenance and for medical care. There is a larger group of self-supporting individuals and families with many children who can pay only a limited amount toward the full cost of adequate medical care insurance. In periods of depression this group is bound to increase.