OBJECTIVES: To evaluate the impact of positive airway pressure (PAP) treatment on healthcare utilization among patients with obstructive sleep apnea (OSA).  METHODS: This retrospective-cohort study was conducted using a large nationally representative administrative claims database. Patients were included in the study if they: (1) were ≥65 years; (2) had a polysomnography (PSG) diagnostic test between 2008 and 2013; (3) had ≥2 medical claims with OSA diagnosis (ICD-9-CM code 327.23) within 1 year after the first PSG test; (4) were newly treated (index) or never treated with PAP after OSA diagnosis; and (5) were continuously enrolled in a plan with medical benefits for 12 months prior and 24 months after the index date. Patients were excluded if they: (1) had claims indicating the use of PAP device, PAP-related supplies, or PAP management prior to the first PSG diagnostic test date; or (2) had a diagnosis of other primary respiratory conditions at baseline. Multivariate logistic regression and negative binomial models were estimated to examine the impact of PAP treatment on all-cause hospitalizations, sleep apnea-related hospitalizations and emergency room (ER) visits.  RESULTS: A total of 24,420 patients (mean age: 72.0±5.1; 58% males) were identified, of which 89% used PAP. Mean Charlson score was not significantly different between patients with PAP and those without PAP (1.44±1.33 vs. 1.46±1.36, p=0.88).  After controlling for potential confounders, patients with PAP were less likely to have an all-cause hospitalization than those without PAP (OR=0.90, 95% CI: 0.82-0.98, p=0.02). Considering frequency, those with PAP had significantly fewer all-cause hospitalizations (RR=0.86, 95 CI: 0.80-0.93, p<0.01), sleep apnea-related hospitalizations (RR=0.86, 95 CI: 0.77-0.97, p=0.01), and ER visits (RR=0.90, 95 CI: 0.85-0.96, p<0.01).  CONCLUSIONS: This study provides new evidence that the use of PAP devices decreases the risk of hospitalizations and ER visits in elderly patients with OSA.