PurposeThis study aimed to assess how pneumonia incidence, health care resource utilization, costs, and hospital length of stay differ by age category in the United States. MethodsA retrospective cross-sectional analysis of the Medical Expenditure Panel Survey database was conducted from 2007 to 2011 for patients with pneumonia. Study outcomes were pneumonia incidence, annual health care utilization, and expenditures across 5 age groups. Early trends of outcomes in the period after introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) (2011) were compared with the pre-PCV13 period (2007–2009). FindingsPneumonia incidence rates for the 1790 patients ranged from 9.2 to 33.0 per 1000 patients. Patients <5 years old had the highest incidence rate at 33.0 per 1000 patients, followed by patients ≥65 years old (27.2 per 1000 patients) and patients ≥45 to <65 years old (14.4 per 1000 patients). The percentages of patients with pneumonia-related hospitalization were 26%, 7%, 15%, 24%, and 46%, respectively (P < 0.0001). Mean (SD) days in hospital stay were 1.73 (0.08), 0.31 (0.50), 0.58 (0.10), 1.86 (0.29), and 3.05 (0.33), respectively (P < 0.05), for patients <5, ≥5 to <18, ≥18 to <45, ≥45 to <65, and ≥65 years old. Mean total pneumonia-related medical costs in patients aged <5 years ($3376; P = 0.009), ≥45 to ≤65 years ($4726; P < 0.0001), and >65 years ($7206; P < 0.0001) were significantly higher compared with patients ≥5 to <18 years old ($1175) after controlling for covariates. Compared with the pre-PCV13 period (2007–2009; n = 1075), a 16% decrease in incidence, a 27% decrease length of stay in hospital, and a 22% decrease in medical costs were observed in the post-PCV13 period (2011; n = 382), although these differences were not statistically significant (P > 0.05). ImplicationsPneumonia remains a disease with significant burden in the United States, and clinical and economic outcomes varied widely by age. Hospitalization for pneumonia has a considerable effect on economic burden, particularly for the very young (<5 years old), middle-aged (≥45 to <65 years old), and elderly (≥65 years old) populations. A trend toward reductions in pneumonia incidence and associated medical costs was observed after the PCV13 was introduced, although these findings were not statistically significant.