Nivolumab After Surgery and Chemotherapy in Treating Patients With Stage IB-IIIA Non-small Cell Lung Cancer (An ALCHEMIST Treatment Trial)

Inclusion Criteria: * Age \>= 18 years * Patients must have undergone complete surgical resection of their stage IB (\>= 4 cm), II or IIIA NSCLC according to the American Joint Committee on Cancer (AJCC) 7th edition and have had negative surgical margins * Baseline chest CT must be performed within 1 month (30 days) prior to randomization to ensure no evidence of disease; if clinically indicated, additional imaging studies must be performed to rule out metastatic disease * Eastern Cooperative Oncology Group (ECOG) performance status 0-1 * Patients must be registered to the ALCHEMIST-SCREEN (ALLIANCE A151216) trial prior to randomization * Non-squamous tumors must not be positive for EGFR exon 19 deletion or exon 21 L858R mutation (centrally as part of the ALCHEMIST-SCREEN protocol) and ALK rearrangement (centrally as part of ALCHEMIST-SCREEN and/or locally) * NOTE: if the results of the central EGFR testing are negative, but the ALK testing was not able to be completed by the ALCHEMIST central lab, the ALK status will be considered negative (unless locally positive for ALK rearrangement) and the patient may be considered for enrollment onto EA5142, once PD-L1 results are received and all other eligibility requirements are met * Tumors must have PD-L1 status tested centrally as part of the ALCHEMIST-SCREEN protocol * Women must not be pregnant or breast-feeding due to unknown and potentially harmful effects of nivolumab on the developing fetus or child * All females of chi…