• Pathologically (histologically or cytologically) proven diagnosis of non-operable stage IIB or III, node positive (American Joint Committee on Cancer \[AJCC\] eighth edition) non-small cell lung cancer (NSCLC) with known PD-L1 status prior to registration

‣ Patients must have an identified primary tumor and at least one nodal metastasis (peribronchial/hilar/intrapulmonary, mediastinal/subcarinal, supraclavicular/scalene)

⁃ Up to 4 cycles of systemic therapy received prior to registration for the current study cancer is allowable; any prior chemotherapy for a different cancer is also permissible

⁃ Patients who refuse surgery, in addition to those who are technically unresectable or medically inoperable, are eligible.

⁃ Patients with separate tumor nodules in the same lobe of the primary tumor are eligible

• The patient must be deemed clinically appropriate for curative intent definitive combined modality therapy, based on the following staging assessments:

‣ History/physical examination prior to registration;

⁃ Magnetic resonance imaging (MRI) scan of the brain (preferred) or CT scan of the brain (if available, contrast is preferred for all neuroimaging) prior to registration;

⁃ CT chest with IV contrast (if contrast is available and unless contraindicated, such as for abnormal kidney function) prior to registration. PET/CT may be used if the CT portion is of identical diagnostic quality as achieved in a stand-alone CT

• No evidence of distant metastases based on FDG PET/CT scan obtained within 60 days of registration

• Primary tumor =\< 7 cm

• Age \>= 18

• Eastern Cooperative Oncology Group (ECOG) performance status 0-2

• Hematologic function (e.g. platelets, leukocytes, hemoglobin) amenable, at the discretion of the treating physician, to allow for treatment with chemotherapy and concurrent radiation therapy

• Creatinine clearance \>= 25 mL/min by the Cockcroft-Gault (C-G) equation

• Subjects with non-malignant pleural effusion are eligible provided the effusion is not known or demonstrated to be an exudative effusion

‣ If a pleural effusion is present, the following criteria must be met to exclude malignant involvement:

• When pleural fluid is visible on both the CT scan and on a chest x-ray, a pleuracentesis is required to confirm that the pleural fluid is cytologically negative;

∙ Effusions that are minimal (i.e., not visible on chest x-ray) that are too small to safely tap are eligible

• Medical history consistent with the patient being amenable, at the discretion of the treating physician, to allow for treating with consolidation immunotherapy. Patients with known EGFR/ALK/other driver mutation at the time of registration are eligible, and these patients can be treated with consolidation systemic therapy at the discretion of the treating physician

• Patients with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen

• Negative pregnancy test =\< 14 days prior to registration for participants of childbearing potential

• The patient or a legally authorized representative must provide study-specific informed consent prior to study entry and, for patients treated in the United States (U.S.), authorization permitting release of personal health information