This report presents selected estimates of costs of complementary and alternative medicine (CAM) use among U.S. adults, the frequency of visits made to CAM providers, and the frequency of purchases of self-care CAM therapies. Data from the 2007 National Health Interview Survey (NHIS), which is conducted by the Centers for Disease Control and Prevention's National Center for Health Statistics, are used in this report. Estimates were derived from the Complementary and Alternative Medicine Supplement of the 2007 NHIS, sponsored by the National Center for Complementary and Alternative Medicine, which is part of the National Institutes of Health. Estimates were generated using the SUDAAN statistical package to account for the NHIS complex sample design. In 2007, adults in the United States spent $33.9 billion out of pocket on visits to CAM practitioners and purchases of CAM products, classes, and materials. Nearly two-thirds of the total out-of-pocket costs that adults spent on CAM were for self-care purchases of CAM products, classes, and materials during the past 12 months ($22.0 billion), compared with about one-third spent on practitioner visits ($11.9 billion). Despite this emphasis on self-care therapies, 38.1 million adults made an estimated 354.2 million visits to practitioners of CAM. About three-quarters of both visits to CAM practitioners and total out-of-pocket costs spent on CAM practitioners were associated with manipulative and body-based therapies. A total of 44% of all out-of-pocket costs for CAM, or about $14.8 billion, was spent on the purchase of nonvitamin, nonmineral, natural products.