Background: In 1997, patients made an estimated 629 million visits to complementary and alternative medicine (CAM) providers; however, little is known about factors associated with visits to CAM providers. Objective: To examine the effect of insurance coverage on frequency of use of CAM providers. Methods: We conducted a nationally representative, random household telephone survey of 2055 adults. Main Outcome Measure: The number of visits made to CAM providers. Results: An estimated 44% of the US population used at least 1 CAM therapy in 1997. Of those using CAM, 52% had seen at least 1 CAM provider in the last year. Among those who used a CAM therapy, factors independently associated with seeing a provider were having been in the upper quartile of visits to conventional providers in the last year (adjusted odds ratio [AOR], 2.00; 95% confidence interval [CI], 1.33-3.01), female sex (AOR, 1.67; 95% CI, 1.17-2.38), and having used the therapy to treat diabetes (AOR, 5.20; 95% CI, 1.40-19.40), cancer (AOR, 2.99; 95% CI, 1.04-8.62), or back or neck problems (AOR, 1.51; 95% CI, 1.02-2.23). Factors independently associated with frequent use (≥8 visits per year) of a CAM provider were full insurance coverage of the CAM provider (AOR, 5.06; 95% CI, 2.45-10.47), partial insurance coverage (AOR, 3.26; 95% CI, 1.72-6.19), having used the therapy for wellness (AOR, 2.85; 95% CI, 1.63-4.98), and having seen the provider for back or neck problems (AOR, 2.26; 95% CI, 1.29-3.94). Conservative extrapolation to national estimates suggests that 8.9% of the population (17.5 million adults) accounted for more than 75% of the 629 million visits made to CAM providers in 1997. Conclusions: A small minority of persons accounted for more than 75% of visits to CAM providers. Extent of insurance coverage for CAM providers and use for wellness are strong correlates of frequent use of CAM providers.