Lukowiak TM, Aizman L, Perz A, et al. - Using data from a large database of patients with commercial insurance and Medicare Advantage coverage, researchers characterized variations in the ratio of basal cell carcinoma (BCC) to cutaneous squamous cell carcinoma (cSCC) in adults (age, ≥18 years). They performed a retrospective evaluation of a large commercially insured cohort based on 985,317 treatment claims from January 1, 2012, to December 31, 2016 using de-identified data from the Optum Clinformatics Data Mart in this cross-sectional analysis. For all demographics, including in Black patients, findings revealed that basal cell carcinomas were more common than cSCCs. Basal cell carcinomas were significantly more prevalent than cSCCs in younger patients. BCCs were 12.6 times more likely for women and 7.2 times more likely for men in populations younger than 40 years. With increasing age, the difference in BCC:cSCC ratios between men and women lessened. Claims data can help us understand the epidemiology of keratinocyte carcinomas in the absence of a national registry.