Background: Women with Stage I endometrioid endometrial carcinomas (EEC) tumors have excellant long term survival. Women may be offered adjuvant radiation if high-risk features are present in the resected tumor. Whole pelvic radiation (EBRT) or vaginal brachytherapy (VB) reduce local recurrence, but do not improve survival. GOG249 looked at the use of chemotherapy with VB in high-grade tumors (HGT). This is a retrospective study using the National Cancer Database to understand national trends in using surgery, radiation and chemotherapy in Stage I EEC. Methods: We identified women with EEC diagnosed between 1998 and 2012 and treated with surgery and/or chemotherapy and/or radiation using the National Cancer Database, with known grade status. Using Chi-squared tests and multivariate logistic regression, we analyzed pathologic stage of EC by age, grade, histology, facility type, race, payor status, income, location, Charlson score, year of diagnosis and facility location. Due to data availability, survival analysis was restricted to patients diagnosed between 2003 and 2007. We used Kaplan-Meier curves and proportional hazards regression to assess overall survival in patients treated with adjuvant EBRT vs VB. Results: Among 241,350 patients identified, patients with HGT had decreased use of EBRT over time from 17% to 5%; the use of VB increased from 7% to 24% (p = 0.0001). There were no significant changes for the use of radiation in patients with low-grade tumors. Patients with age > 70 were more likely to receive radiation than patients < 70, but less likely to receive chemotherapy (p = 0.0001). The use of chemotherapy in all patients increased from 1% to 14% over time. Multivariate analysis demonstrated that patients with HGT had 84% 5 year survival with VB vs 78% for patients receiving EBRT (HR 0.85 vs 1.16, p = 0.0001). In patients with low grade tumors there was no advantage for the use of VB and ERBT decreased survival. The use of chemotherapy did not improve survival. Conclusions: The use of VB and chemotherapy has been increasing over time for patients with HGT. However, the use of chemotherapy may not improve survival in this highly curable population, while the use of EBRT is demonstrated to decrease survival.