Prior to accrual on the trial, patients with Stage IV NSCLC will be treated with standard first-line chemotherapy. Patients who achieve a partial response or stable disease by imaging criteria with fewer than or equal to six sites of oligometastatic disease will be randomized to maintenance chemotherapy or consolidative SBRT to all sites of disease (followed by maintenance chemotherapy at the medical oncologist's discretion). Choices of first line and maintenance chemotherapy will be determined by the medical oncologist based on clinical appropriateness.