Purpose: To better define patterns of practice for patients with non-small cell lung cancer (NSCLC) in the United States. Methods and Materials: A survey of 36 questions was designed to collect information regarding practice patterns of radiation oncologists for the management of patients with NSCLC. All American Society for Radiation Oncology members were invited to respond. Results: Four hundred twenty-four responses from radiation oncologists in the United States were received. The response rate for the survey was approximately 20%. Substantial discrepancies were seen in the use of stereotactic body radiation therapy (SBRT) for patients with peripherally and centrally located early-stage tumors and in the recommended SBRT dose. There was a near consensus opinion regarding the use of concurrent chemotherapy and the radiation dose for patients with inoperable stage II and III NSCLC with a good performance status; however, in patients with a poor performance status or in patients with stage IV disease treatment recommendations differed remarkably. Additionally, the use of elective nodal irradiation and the assessment of tumor motion during simulation were highly variable. Thoracic radiation oncologists were more likely to prescribe higher doses, omit elective nodal irradiation, and use advanced technologies (P < .001). Conclusions: Substantial variations were seen in the management of patients with stage I and IV NSCLC in addition to the incorporation of new technology. This information can be used to help design meaningful clinical trials. © 2014 American Society for Radiation Oncology.