ObjectiveThe modified 5‐item frailty index (mFI‐5) is a comorbidity‐based risk stratification tool previously validated in patients undergoing several surgical procedures. This study investigates the association between mFI‐5 score and cricopharyngeal myotomy (CM) complications.Study DesignRetrospective database review.SettingUS hospitals.MethodsThe National Surgical Quality Improvement Program database was queried for patients who underwent CM between 2005 and 2018. mFI‐5 score was determined by assigning 1 point for comorbidities including: diabetes mellitus, hypertension, congestive heart failure, chronic obstructive pulmonary disease, and dependent health status. Univariate and multivariable analyses were conducted to determine associations between mFI‐5 score and postoperative complications.ResultsA total of 1075 patients undergoing CMs were queried and stratified into the following groups: mFI = 0 (n = 412 [38.3%]), mFI = 1 (n = 452 [42.0%]), and mFI ≥ 2 (n = 211 [19.6%]). Univariate analysis showed association between higher mFI‐5 scores with older age, higher American Society of Anesthesiologists Classification class, obesity, smoking, dyspnea, and systemic sepsis. Higher mFI‐5 was associated with a greater proportion of cumulative surgical complications, cumulative medical complications, pneumonia, myocardial infarction, cumulative morbidity, readmissions, unplanned readmissions, and reoperations. Multivariable analyses found associations between greater mFI‐5 score and cumulative morbidity (odds ratio [OR] = 1.95, confidence interval [CI]: 1.29‐2.96, P = .002), any surgical complication (OR = 1.80, CI: 1.15‐2.79, P = .010), readmission (OR = 1.81, CI: 1.01‐3.26, P = .047), and reoperations (OR = 1.96, CI: 1.04‐3.68, P = .037).ConclusionEvaluating mFI‐5 can help assess the risk of postoperative complications for patients undergoing CM.Level of EvidenceLevel 4.