Studies suggest that the presence of multiple chronic conditions (MCC) adds a layer of complexity to disease management; recently the U.S. Department of Health and Human Services established a strategic framework for improving the health of this population. This report presents estimates of the population aged 45 and over with two or more of nine self-reported chronic conditions, using a definition of MCC that was consistent in the National Health Interview Survey (NHIS) over the recent 10-year period: hypertension, heart disease, diabetes, cancer, stroke, chronic bronchitis, emphysema, current asthma, and kidney disease. Examining trends in the prevalence of MCC informs policy on chronic disease management and prevention, and helps to predict future health care needs and use for Medicare and other payers.