PURPOSE:To describe the prevalence of strabismus and strabismus surgery in the aged Medicare fee-for-service population. METHODS:A 5% random sample of Medicare Part B physician claims was used to identify beneficiaries ≥ 65 years of age with strabismus and those undergoing strabismus surgery between 2002 and 2010. RESULTS:In 2010 there were 1,237,469 beneficiaries. The diagnosis of strabismus was made in 8,470 (0.68%), more often in females (56%) and in whites (92%). Common diagnoses were paralytic strabismus, exotropia, and esotropia, with each reported in 22%. Strabismus surgery in 2010 was performed on 197 patients (0.016% of all beneficiaries), or approximately 2.3% of patients with the diagnosis of strabismus. Horizontal surgical codes were reported most frequently (68%). Reoperations were reported for 23% and adjustable sutures for 23% of cases. The prevalence of strabismus surgery ranged from 183 to 236 cases annually (0.015%-0.018%). Review of pooled data (2002-2010) found that the prevalence of strabismus increased with age from 65 to 89 years of age (P < 0.0001) and that whites underwent strabismus surgery more often than African Americans (0.017% vs 0.007%, respectively; P < 0.0001). CONCLUSIONS:Less than 1% of aged Medicare beneficiaries are diagnosed with strabismus each year, with the rate increasing significantly with age. Strabismus surgery is performed annually in 16 of 100,000 of aged Medicare beneficiaries; the surgery rate is significantly lower among African Americans. Understanding the reasons for the difference by race/ethnicity deserve further study.