Background: It is unknown whether there is a benefit to initiating triple therapy (TT; inhaled corticosteroids combined with long-acting β 2-agonists and long-acting muscarinic antagonists) promptly (within 30 days) following a chronic obstructive pulmonary disease (COPD)-related hospitalization or emergency-department (ED) visit compared with delaying treatment (31-180 days). Methods: This retrospective, observational study (GSK: HO-15-15256) used healthcare claims from a commercial and Medicare claims database (January 1, 2008-December 31, 2015). Patients: ≥40 years of age, diagnosed with COPD and no history of TT 12 months pre-index. Patients experiencing a COPD-related hospitalization or ED visit (index) who initiated TT ≤ 6 months following index were included (January 1, 2009-December 31, 2014). Patients initiating TT ≤ 30 or 31-180 days following index were included in the Prompt or Delayed cohorts, respectively. All-cause and COPD-related costs (total, medical and prescription), and exacerbations (severe and moderate) per patient per year were determined for 12 months post index. Outcomes were adjusted by cohort, weighted for a balanced distribution of baseline covariates between cohorts using inverse probability weights. Results: Overall, 10,902 patients were identified (Prompt: n = 5701; Delayed: n = 5201). Total, medical and prescription all-cause costs were significantly higher in the Delayed versus Prompt cohorts (percent increase: 18.7%, 22.8% and 8.8%, respectively; all p < 0.0001). COPD-related total, medical and prescription costs were 49.3%, 66.3% and 10.3% higher in the Delayed versus Prompt cohorts, respectively (all p < 0.0001). Total and severe COPD-related exacerbation rates were 28.2% and 64.7% higher in the Delayed versus Prompt cohorts (p < 0.0001). Conclusion: Prompt use of TT following a COPD-inpatient or ED visit may reduce future costs and subsequent exacerbations compared with delaying the initiation of TT.