Background: SBRT is the standard of care for patients (pts) with early stage NSCLC who are not surgical candidates due to co-morbidities. Current NCCN guidelines state that IRLNE prior to definitive treatment for stage IA NSCLC is optional. Performing SBRT without IRLNE may increase the risk for occult nodal metastasis that could lead to regional recurrences and impact survival, however small retrospective studies have failed to demonstrate any benefit of IRLNE. Prior studies have also shown that delay in time to surgery impacts survival in stage 1 NSCLC pts, and due to co-morbidities SBRT pts are more likely to have a delayed time to radiation. However, the impact of time to radiation on OS in such pts is not well defined. Methods: We queried the NCDB for pts with stage 1 NSCLC treated with SBRT diagnosed from 2004 to 2014. We identified whether regional lymph nodes were examined for these pts. In addition, we obtained data regarding other clinicopathologic and treatment associated variables. Kaplan Meier method was used for survival analysis. Cox proportional hazards model was used to assess the impact of the co-variates on OS. Results: We identified 15,338 pts with stage 1 NSCLC treated with SBRT. Of these, 943 pts had IRLNE. Median age was 75 years (range 26-90) and Charlson-Deyo score was ≥ 1 in 6,427 pts. Median OS was 35.4 months (95% CI 34.6-36.2 months). The median time to radiation from diagnosis was 57 days. In a multivariate analysis, there was no impact of IRLNE on OS. Other clinicopathologic variables that impacted OS are listed in the table. A delay in initiation of radiation was associated with significantly worse OS. Conclusions: Invasive staging prior to SBRT for stage I NSCLC does not impact OS. A delay in initiating definitive radiation adversely affects survival in this population and the risk is incremental per week delay.