['Multiple population-based studies have suggested increasing omission of radiation therapy in favor of alternative treatment strategies in lymphomas, with an associated negative impact on survival. Radiation therapy has long been considered the standard management for many mucosa-associated lymphoid tissue lymphomas. Thus, we aimed to evaluate patterns of treatment utilization and survival.', 'A retrospective analysis based on the National Cancer Database was performed on 22,378 patients with splenic, nodal, or extranodal stage I-II marginal zone lymphoma diagnosed between 1998 and 2012. A logistic regression model was used to assess the association between sociodemographic, tumor, and treatment characteristics and the utilization of radiation therapy. Multivariate propensity score-adjusted Cox proportional hazards models were performed to identify factors independently associated with overall survival (OS).', 'Of 22,378 patients, 82% had stage I disease, 77% had extranodal mucosa-associated lymphoid tissue lymphoma, 5% had splenic marginal zone lymphoma, and 64% were older than 60 years. Radiation therapy utilization decreased from a peak of 39% in 2007 to 33% in 2011 (P < .001), with a corresponding significant increase in systemic therapy utilization. Radiation therapy was associated with a 5- and 10-year OS of 86.7% and 68.8% compared with 78.3% and 54.3% for no radiation therapy (P < .001). On multivariate propensity score-adjusted survival analysis, radiation therapy remained independently associated with improved OS (hazard of death, 0.75; 95% confidence interval, 0.65-0.85; P < .001).'] Does underutilization of radiation therapy in early-stage marginal zone lymphoma negatively impact overall survival?