OBJECTIVES: To estimate the likelihood of trauma center admission for injured elderly patients with trauma, determine trends in trauma center admissions, and identify factors associated with trauma center use for elderly patients with trauma. DESIGN: Retrospective analysis. SETTING: Acute care hospitals in California. PATIENTS: All patients hospitalized for acute traumatic injuries during the period from January 1, 1999, to December 31, 2008 (n = 430,081). Patients who had scheduled admissions for nonacute or minor trauma were excluded. MAIN OUTCOME MEASURE: Likelihood of admission to level I or II trauma center was calculated according to age categories after adjusting for patient and system factors. RESULTS: Of 430,081 patients admitted to California acute care hospitals for trauma-related diagnoses, 27% were older than 65 years. After adjusting for demographic, clinical, and system factors, compared with trauma patients aged 18-25 years, the odds of admission to a trauma center decreased with increasing age; patients aged 26-45 years had lower odds (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.71-0.80) of being admitted to a trauma center for their injuries than did patients 46-65 years of age (OR, 0.57; 95% CI, 0.54-0.60), patients 66-85 years of age (OR, 0.35; 95% CI, 0.30-0.41), and patients older than 85 years (OR, 0.30; 95% CI, 0.25-0.36). Similar patterns were found when stratifying the analysis by trauma type and severity. Living more than 50 miles away from a trauma center (OR, 0.03; 95% CI, 0.01-0.06) and lack of county trauma center (OR, 0.17; 95% CI, 0.09-0.35) were also predictors of not receiving trauma care. CONCLUSION: Age and likelihood of admission to a trauma center for injured patients were observed to be inversely proportional after controlling for other factors. System-level factors play a major role in determining which injured patients receive trauma care.