The New England Regional Infant Cardiac Program (NERICP) is a voluntary association of all hospitals in the New England states which offer definitive care for infants with heart disease. With the purpose of improving infant cardiac care, the program began in 1968 and continues to the present. Specific activities include professional education to improve case finding and earlier referral; identification and subsidy of appropriate transportation facilities; improved communications with participating hospitals; subsidy of follow-up where needed; provision for room and board for indigent parents when their baby has been moved some distance from home; continuing nursery nurse education in the recognition of infants with heart disease. All participating hospitals agreed to tabulation of their entire experience with infants with heart disease (3,626 infants in nine years). Case histories of surviving infants have been updated systematically. The period of July 1968 to June 1974 was selected for this detailed analysis because data from this period form the basis of an ongoing long-term follow-up study and have been re-verified several times. This analysis is confined to the first year of life. More recent data, July 1974 to June 1977, are discussed separately and italicized numerical data from 1974 to 1977 have been added to tables where the results may be of interest. In the early years, case finding rose by 20% and has continued to increase gradually. By 1976, there were 2.4 NERICP infants per 1,000 live births identifiable in the New England states. Surveys of state vital statistics showed a 50% decrease in infants who died with heart disease who did not reach a participating hospital. Neonates are admitted to participating hospitals earlier; admissions of infants less than 2 days old increased from 20% in 1968 to 34% in 1977. Of infants admitted in 1977, more than 50% were in the first week of life. During the period of study from 1969 to 1974, there was a consolidation of hospital services for infants with heart disease. Of the initial 11 participating hospitals in 1969, by 1974, there were five hospitals offering a full range of cardiac services, three hospitals offering limited surgical services, two hospitals no longer performing cardiac catheterization or cardiac surgery in infants, and one hospital which had discontinued all pediatric cardiology. Despite expected differences in case finding, the patient material and management of patients among the various hospitals were surprisingly comparable. There was little variation in the kinds of heart disease encountered over the years, among the states and among the hospitals. There was a significantly higher mortality among infants whose birthweight was less than 2.0 kg and among infants who had additional, severe noncardiac anomalies. Mortality was significantly higher for infants admitted in the first days or weeks of life and cardiac surgery resulted in higher mortalities in this age group. Among the many specific anatomic diagnostic categories, there was little change in outcome during the years 1969 to 1974. Subsequently, immediate, 30-day survival of surgical procedures shows improvement whether viewed by age at surgery, diagnosis, operative procedure or years. The introduction of early reparative surgery, as opposed to early palliative surgery followed by late repair, occurred in 1973. Subsequent data show an increasing number of "open heart" procedures in infants with steadily improving 30-day mortality. A similar fall in mortality for closed heart procedures was documented. Results of palliation versus repair for ventricular septal defects, transposition of the great arteries and tetralogy of Fallot were investigated. The average number of days of hospitalization, the numbers of cardiac catheterizations, and the numbers of cardiac operations were evaluated. By using hospital charges for 1975, the estimated cost for care of an average cardiac infant for the first year of life ranged from $3,800 to $7,200 (average $6,600). Among the hospitals the payments by state agencies for hospital costs in the first year of life were estimated to range from $4,300 to $8,000 per patient for the same year. Because NERICP can provide detailed data on a consecutive series of infants from a finite geographic area, epidemiologic information can be gleaned. (Am J Epidemiol 104:527, 1976; Am J Epidemiol 109:433, 1979). Similarly, detailed experience with the various anatomic cardiac lesions was extracted and is presented as a guideline for expected average experience for regions outside of New England.