ObjectiveTo evaluate the long-term survival of patients with T1a-bN0M0 non-small cell lung cancer (NSCLC) after sublobar resection. MethodsPatients with T1a-bN0M0 NSCLC who underwent sublobar resection from 2004 to 2015 were selected from the Surveillance, Epidemiology, and End Results (SEER) database, and divided into a segmentectomy group and a wedge resection group according to the resection method. After propensity-score matching (PSM) at a ratio of 1:1, the overall survival (OS) and disease-specific survival (DSS) of patients were analyzed using Cox regression model, log-rank test, and restricted mean survival time (RMST). ResultsA total of 3262 patients were included in the study, including 1321 males and 1941 females, with a median age of 69.0 years. Among them, 2419 patients were in the wedge resection group and 843 patients were in the segmentectomy group. After matching, 843 pairs of patients were obtained. The results showed that the DSS death risk of the segmentectomy group was lower than that of the wedge resection group [HR=0.82, 95%CI (0.68, 0.98), P=0.030], but there was no statistical difference in the OS death risk [HR=0.90, 95%CI (0.79, 1.02), P=0.107]. The 10-year DSS rate (68.0% vs. 60.6%, P=0.011) and 10-year OS rate (40.8% vs. 37.0%, P=0.049) of the segmentectomy group were better than those of the wedge resection group, while there was no statistical difference in the 5-year DSS rate (82.9% vs. 79.5%, P=0.112) or 5-year OS rate (68.9% vs. 64.9%, P=0.096). Subgroup analysis showed that segmentectomy had a better 10-year OS-RMST in patients with adenocarcinoma (P=0.045), right lower lobe tumor (P=0.014), and tumor diameter≤1.6 cm (P=0.006). ConclusionIncreasing lymph node dissection during sublobar resection may improve prognosis. Compared with wedge resection, segmentectomy may improve the long-term DSS rate of patients with T1a-bN0M0 NSCLC.