Background: Stage IIIA non-small cell lung cancer (NSCLC) is a heterogeneous disease treated by surgery-based approach or definitive chemoradiation (CRT) and immunotherapy (ICI) consolidation. Studies have shown that black patients in general are diagnosed at advanced stages, are less likely to receive ICI, and have lower overall survival (OS) compared to whites. Importantly, ICI was shown to impart similar or even better OS among advanced-stage black NSCLC patients, compared to whites. Geographical location and socioeconomic status have also been shown to affect outcomes. There are no studies on sociodemographic factors affecting survival in stage IIIA NSCLC in the ICI era. Methods: We used National Cancer Database (NCDB) to identify 23,110 patients with clinical stage IIIA NSCLC treated with either surgery-based approach or definitive CRT followed by ICI during 2017-2019, and surgery-based treatment or CRT during 2014-2016. We analyzed age, race, sex, insurance type, income, geographic location, Charlson Comorbidity Index (CCI) and education. Kaplan-Meier (KM) plots were used to examine survival curves and descriptive analysis was performed to examine the characteristics of sociodemographic variables by the two treatment modalities. Cox regression analysis was used to identify factors associated with OS. Results: ICI maintenance improved the OS of all stage IIIA NSCLC patients after CRT during 2017-2019 compared to CRT only in 2014-2016. On multivariate analysis of surgical and CRT-ICI cohorts, blacks had slightly better OS compared to whites (HR, 95%CI, p-value) (0.89, 0.84-0.95, < 0.001) but lower than other races including Asians (0.77, 0.69-0.87, < 0.001). While there was no OS difference in the surgical arm (0.94, 0.83-1.07, p = 0.356) between black and white patients, better survival was seen in blacks in the CRT-ICI arm (0.88, 0.82-0.94, < 0.001). No significant interaction between race and CRT-ICI was identified which indicates the benefit of CRT-ICI is independent of the race effect. Other factors associated with lower OS were older age with age > 75 HR 1.00, ages 19-39 (0.47, 0.35-0.64) ages 40-64 (0.71, 0.67-0.75), ages 65-74 (0.79, 0.76-0.83), median quartile income < $40,227 (1.07, 1.01-1.14), non-metro location (1.12, 1.07-1.17), non-academic facility (1.09, 1.05-1.14), and male sex (1.24, 1.20-1.29). Insurance status had no effect on OS. Conclusions: Our study indicates that there is no survival difference between white and black patients treated with surgery, but blacks had better survival when treated with CRT-ICI. Racial disparity in NSCLC survival depends on stage and access to care. Treatment modality, income, metro location, and access to an academic center are more significant predictors of survival than race. Interestingly, health insurance had no impact on OS.