BACKGROUND: Surgical stabilization of rib fracture (SSRF) is increasingly used to manage patients with rib fractures. Benefits of performing SSRF appear variable, and the procedure is costly, necessitating cost-effectiveness analysis for distinct subgroups. We aimed to assess the cost-effectiveness of SSRF versus nonoperative management among patients with rib fractures younger than 65 years versus 65 years or older, with versus without flail chest. We hypothesized that, compared with nonoperative management, SSRF is cost-effective only for patients with flail chest. METHODS: This economic evaluation used a decision-analytic Markov model with a lifetime time horizon incorporating US population-representative inputs to simulate benefits and risks of SSRF compared with nonoperative management. We report quality-adjusted life years (QALYs), costs, and incremental cost-effectiveness ratios. Deterministic and probabilistic sensitivity analyses accounted for most plausible clinical scenarios. RESULTS: Compared with nonoperative management, SSRF was cost-effective for patients with flail chest at willingness-to-pay threshold of US $150,000/QALY gained. Surgical stabilization of rib fracture costs US $25,338 and US $123,377/QALY gained for those with flail chest younger than 65 years and 65 years or older, respectively. Surgical stabilization of rib fracture was not cost-effective for patients without flail chest, costing US $172,704 and US $243,758/QALY gained for those younger than 65 years and 65 years or older, respectively. One-way sensitivity analyses showed that, under most plausible scenarios, SSRF remained cost-effective for subgroups with flail chest, and nonoperative management remained cost-effective for patients older than 65 years without flail chest. Probability that SSRF is cost-effective ranged from 98% among patients younger than 65 years with flail chest to 35% among patients 65 years or older without flail chest. CONCLUSIONS: Surgical stabilization of rib fracture is cost-effective for patients with flail chest. Surgical stabilization of rib fracture may be cost-effective in some patients without flail chest, but delineating these patients requires further study. LEVEL OF EVIDENCE: Economic/decision, level II.