To our knowledge, this study is the first to report the genomic and immune microenvironment features in NSCLC patients with Ex20ins of EGFR or HER2. In our dataset, EGFR Ex20ins alterations were identified in 35 cases (6.9% of EGFR‐mutant NSCLC and 2.8% of all NSCLC), and HER2 mutations were detected in 1.7% of NSCLC patients. Here, ERBB2 is linked to non-small cell lung carcinoma.