304 Background: Evidence suggests that the number and type ofcomorbidities at cancer diagnosis influences cancer treatment and mortality, especially among older patients.We sought to describe comorbidity patterns and identify how patterns predict all-cause mortality among older non-Hodgkin lymphoma (NHL) patients. Methods: Using the linked Surveillance, Epidemiologic, and End Results (SEER)-Medicare databases, we identified patients aged > 66 with a first diagnosis of stage I-IV NHL from 2007-2009. Codes for individual comorbidities in the Charlson Comorbidity Index (CCI) were identified in the 12 months before NHL diagnosis, during which patients were required to have continuous Medicare Parts A, B, and D enrollment and no managed care. The prevalence of single and concurrent comorbidities was calculated. Medicare enrollment files contained vital status. We used multivariable Cox proportional hazard models to estimate adjusted hazard ratios (aHR) for all-cause mortality in each comorbidity group versus no comorbidity controlling for age, sex, race/ethnicity, stage, tumor growth category, and other comorbidities. Results: Among 4901 older NHL patients, 52% had ≥ 1 comorbidity and 26% had a CCI > 2. The most prevalent comorbidities were diabetes (25%), chronic obstructive pulmonary disorder (COPD) (16%), and congestive heart failure (CHF) (12%). All-cause mortality was greater among patients with CHF (aHR = 1.44; 95%CI = 1.26, 1.65), diabetes (aHR = 1.16; 95%CI = 1.03,1.29), or dementia (aHR = 1.20; 95%CI = 1.03, 1.41) compared to those without each comorbidity. More than half of diabetes patients, two-thirds of COPD patients, and three-quarters of CHF patients had > 1 additional non-cancer comorbidity. All-cause mortality was higher among NHL patients with CHF who had co-occurring COPD (aHR = 1.56; 95%CI = 1.19, 2.05), diabetes (aHR = 1.66; 95%CI = 1.29, 2.14), or both COPD and diabetes (aHR = 2.61; 95%CI = 1.97, 3.46). Conclusions: Comorbidity is common among older, newly-diagnosed NHL patients and should be carefully considered when making treatment decisions. Given the known cardiotoxicity of the main NHL chemoimmunotherapy, providers should discuss comorbidity management, particularly for CHF, before initiating therapy.