OBJECTIVES: Patients with COPD are at increased risk for lung infections, such as pneumonia. However, few studies have evaluated the impact of pneumonia on health care resource utilization (HCRU) and cost in this population. The objective of this study is to estimate HCRU and cost in COPD patients with newly acquired pneumonia, compared to those without pneumonia. METHODS: A retrospective analysis using MarketScan® Commercial Claims and Encounters and Medicare Supplemental Databases was conducted. COPD patients with and without newly diagnosed pneumonia between January 1, 2005 and September 30, 2010 were identified. Propensity score matching was used to create a one-to-one matched cohort. Patient demographics, comorbidities measured by Charleston Comorbidity Index (CCI), and medication use were evaluated before and after matching. HCRU, including the number of hospitalizations, emergency room (ER), and outpatient visits, length of hospital stay (LOS), and associated healthcare costs were assessed during the 12-month follow up. Two-part models and gamma regression models were conducted to compare costs between groups after matching. RESULTS: In the baseline cohort of 520,008 patients, newly acquired pneumonia patients were older (mean age: 70 vs. 63 years) and sicker (CCI: 3.25 vs. 2.67). After matching, no baseline covariates were statistically different between groups. In the matched cohort of 168,260 patients, one-year mean HCRU after pneumonia onset was significantly higher (all p<0.0001) for inpatient visits (1.2 vs. 0.29), ER visits (1.9 vs. 0.68), outpatient visits (34.97 vs. 23.1) and LOS (7.3 vs. 1.3 days) than the control cohort. Estimated one-year mean costs were higher in the pneumonia cohort with differences in: inpatient costs $14,353 (95% CI: $14,037, $14,690), outpatient costs $6,891 ($6,706, $7,075), prescription drug costs $1,104 ($1,054, $1,152) and total costs $23362 ($22,969, $23,787). CONCLUSIONS: Our study demonstrates elevated HCRU and costs in COPD patients after acquiring pneumonia.