Objectives: Completeness and timeliness are key attributes of accurate disease surveillance. This study aimed to evaluate the completeness and timeliness of tuberculosis (TB) notification in the Republic of Korea, by comparing notification data from the Korean National Tuberculosis Surveillance System and reimbursement data from the National Health Insurance. Methods: We evaluated reimbursement data from 103,075 cases (2012–2014) and surveillance data from 215,055 cases (2011–2015); cases were matched using Resident Registration Numbers. Completeness was evaluated using notifications that were reported within 365 days of the corresponding insurance claim. Timeliness was evaluated using the delay between starting TB treatment and the corresponding notification. Multivariate logistic regression analysis was used to analyze factors that affected completeness (e.g., sex, age, institution type, and nationality). Results: The completeness values were 90.0% in 2012 (33,094/36,775), 93.0% in 2013 (31,445/33,803), and 94.0% in 2014 (30,537/32,497). The rates of notification within 7 days of the corresponding claim were 81.6% in 2012 (27,323/33,489), 79.8% in 2013 (25,469/31,905), and 80.4% in 2014 (24,891/30,978). Increases over time were observed in the sex-, age-, institution type-, and nationality-specific analyses. Multivariate analyses revealed that completeness was affected by institution type [hospitals: odds ratio (OR) = 1.82, p < 0.001; general hospitals: OR = 4.18, p < 0.001] and nationality (native Korean status: OR = 1.48, p < 0.001). Conclusion Notification completeness exhibited a 4.0% increase during 2012–2014 in Korea, and institution type and nationality significantly affected the completeness of TB notifications.