Catheter ablation for atrial fibrillation (AF) improves outcomes compared with medical treatment alone. Risk stratification for outcomes following AF ablation remains an important area of uncertainty. This analysis evaluated the association between frailty and outcomes following AF ablation. We evaluated US inpatients receiving AF ablation between January 1, 2016 and December 1, 2016 using Medicare fee-for-service billing codes. Diagnosis codes were used to calculate patients' Hospital Frailty Risk Score, with the cohort divided according to established cut-points of low (<5), intermediate (5 to 15), and high (>15) risk for frailty. The primary outcome was survival. Among 5,070 in patients treated with catheter ablation (mean age 74.9 6.8 years, 51.1% female), 38.6% were defined as frail with a Hospital Frailty Risk Score >5, including 8.3% at high risk. Mortality rates (up to 630 days) were 5.8% in the low-risk group, 23.4% in the intermediate-risk group, and 42.2% in the high-risk group (log-rank p values <0.001 for comparison between categories). In restricted cubic spline regression analysis, the adjusted hazard ratios for long-term mortality monotonically increased with increasing values of the Hospital Frailty Risk Score (adjusted hazard ratio 1.065, 95% confidence interval 1.054 to 1.077). In secondary end points, frailty was independently associated with length of stay, postprocedure 30-day mortality, 30-day readmission and postdischarge 30-day mortality rates. In conclusion, frailty as assessed by a claims-based score is common in inpatient recipients of AF ablation, and provides risk stratification for mortality and other key clinical outcomes.