Background: Topical tretinoin is effective treatment for both acne and photoaging. This creates a problem for insurers that cover medication costs, because treatment of acne is often covered but treatment of photoaging is not. The age distributions of patients with acne or photoaging are likely to be very different. Therefore, one approach insurers can use is an age cutoff for covering the cost of topical tretinoin therapy. Objective: Our purpose was to determine at what age patients are more likely to receive tretinoin for treatment of acne vulgaris versus other conditions to provide a rational basis for insurers to set coverage cutoffs. Methods: National Ambulatory Medical Care Survey data for the years 1990 to 1994 were analyzed to ascertain the age distribution of acne vulgaris office visits and treatment with topical acne agents including tretinoin. These data were compared to office visits and tretinoin treatment of wrinkles, solar elastosis, and other conditions. Results: The mean age (± standard deviation) of patients seen for acne vulgaris was 24.3 ± 11.5 years old. The age distribution of topical tretinoin treatment paralleled the age distribution of acne. Tretinoin treatment of acne and of nonacne conditions were equal at an age of 44. Conclusion: The distribution of outpatient visits for acne treatment is skewed toward older patients and persists beyond age 40. A rational age cut-off for coverage of topical tretinoin treatment is 40 years.(J Am Acad Dermatol 1998;38:221-6.)