Advances in early diagnosis and curative treatment have reduced high mortality rates associated with non-small cell lung cancer. However, racial disparity in survival persists partly because Black patients receive less curative treatment than White patients. We performed a 5-year pragmatic, trial at five cancer centers using a system-based intervention. Patients diagnosed with early stage lung cancer, aged 18-85 were eligible. Intervention components included: (1) a real-time warning system derived from electronic health records, (2) race-specific feedback to clinical teams on treatment completion rates, and (3) a nurse navigator. Consented patients were compared to retrospective and concurrent controls. The primary outcome was receipt of curative treatment. There were 2841 early stage lung cancer patients (16% Black) in the retrospective group and 360 (32% Black) in the intervention group. For the retrospective baseline, crude treatment rates were 78% for White patients vs 69% for Black patients (P < 0.001); difference by race was confirmed by a model adjusted for age, treatment site, cancer stage, gender, comorbid illness, and income-odds ratio (OR) 0.66 for Black patients (95% CI 0.51-0.85, P = 0.001). Within the intervention cohort, the crude rate was 96.5% for Black vs 95% for White patients (P = 0.56). Odds ratio for the adjusted analysis was 2.1 (95% CI 0.41-10.4, P = 0.39) for Black vs White patients. Between group analyses confirmed treatment parity for the intervention. A system-based intervention tested in five cancer centers reduced racial gaps and improved care for all. © 2019 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.