To determine differences in eye care utilization by frailty levels among Medicare beneficiaries with glaucoma. Retrospective cohort study. Medicare fee-for-service beneficiaries over 65 years of age with glaucoma, identified using International Classification of Diseases codes before July 1,2014. By using a validated claims-based frailty index (range, 0-1), beneficiaries were classified as nonfrail/prefrail (0-0.19), mildly frail (0.20-0.29), and moderate-to-severely frail (≥ 0.30). Negative binomial regression analyses were used to estimate incident rate ratios (IRRs) of eye care utilization by frailty levels between July 1, 2014, and December 31,2016. Current Procedural Terminology codes for eye examinations and eye care-related office visits; eye care-related inpatient and emergency department (ED) encounters; eye care-related nursing facility and home-visit encounters; visual field (VF) and retinal nerve fiber layer (RNFL) OCT tests; and selective laser trabeculoplasties (SLTs) and glaucoma surgeries. Among 76 260 Medicare beneficiaries with glaucoma, the mean age was 78.9 years (standard deviation, 7.8), female beneficiaries constituted 60.5%, and 78.7% of beneficiaries self-identified as non-Hispanic White. According to a claims-based frailty index, 79.5% of beneficiaries were nonfrail/prefrail, 17.1% were mildly frail, and 3.4% were moderate-to-severely frail. Moderate-to-severely frail beneficiaries were less likely than nonfrail/prefrail beneficiaries to have outpatient encounters (IRR, 0.85, 95% confidence interval [CI], 0.83-0.88); VF tests (IRR, 0.64, 95% CI, 0.60-0.67); RNFL OCT tests (IRR, 0.77, 95% CI, 0.73-0.81); SLT (IRR, 0.74, 95% CI, 0.60-0.92); and glaucoma surgery (IRR, 0.74, 95% CI 0.55-0.99), after adjusting for age, gender, glaucoma severity, race, and socioeconomic status. Compared with nonfrail/prefrail beneficiaries, moderate-to-severely frail beneficiaries had higher rates of inpatient/ED encounters (IRR, 5.03, 95% CI, 2.36-10.71) and nursing facility/home-visit encounters (IRR, 34.89, 95% CI, 14.82-82.13). Compared with nonfrail/prefrail Medicare beneficiaries with glaucoma, beneficiaries with moderate-to-severe frailty had lower rates of eye care utilization in the outpatient setting and higher rates of utilization in acute care settings. This suggests that frail patients may receive less disease monitoring and fewer interventions for their glaucoma management. Proprietary or commercial disclosure may be found after the references.