Background: Gatekeeper-paradigm managed care systems may discourage the use of dermatologists in the management of skin conditions by limiting direct access. This may limit the quality of care patients with skin disorders receive and may be an inefficient use of medical resources. Objective: The purpose of this study was to determine the likelihood that patients with dermatologic conditions who see a primary care provider will be referred to a dermatologist. Methods: Data on the disposition of outpatient visits to primary care physicians for one and only one dermatologic diagnosis were obtained from the 1990-1994 National Ambulatory Medical Care Survey. These data were used in an econometric model to estimate the likelihood of referral to a dermatologist for an episode of care. Results: Of all visits for a single dermatologic diagnosis, 39% were to primary care physicians. The disposition of referral was more common for these dermatology-related visits than for all office visits to primary care physicians (5.8% vs 4.5%, P < .001). The most frequent diagnoses associated with referral were common dermatologic problems, not rare disorders. The number of visits per episode of care was highly dependent on the assumptions of the analysis, resulting in estimate ranges for referral rates per episode between 6.8% and 18.5% for pediatricians, 8.2% and 23% for family and general practitioners, and 16.6% and 46.5% for internists. Conclusion: The relative difficulty for primary care providers of managing skin problems is reflected by their frequent need to refer patients with common skin problems and by the greater likelihood of referral for skin disorders than for other medical conditions. The high rates of referral per episode of care supports the cost-effectiveness of direct access to dermatologists. (J Am Acad Dermatol 1999;40:426-32.)