This study examines the impact of advancements in lung-cancer treatment on population mortality, focusing on the distinct subtypes of non–small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). Using data from the Surveillance, Epidemiology, and End Results (SEER) program, the researchers assessed lung-cancer mortality and linked deaths from lung cancer to incident cases in SEER cancer registries. This allowed them to evaluate population-level mortality trends attributed to specific subtypes, known as incidence-based mortality. The results showed that mortality from NSCLC decreased more rapidly than incidence, primarily due to improvements in survival over time, which were associated with the approval and use of targeted therapies. For example, among men, incidence-based mortality from NSCLC decreased by 6.3% annually from 2013 to 2016, while the incidence decreased by 3.1% annually from 2008 to 2016. Lung cancer-specific survival improved from 26% among men with NSCLC diagnosed in 2001 to 35% among those diagnosed in 2014. Similar patterns were observed among women with NSCLC. In contrast, mortality from SCLC declined mainly due to a decrease in incidence, with no significant improvement in survival. The study concludes that the sharp decline in population-level mortality from NSCLC in the United States from 2013 to 2016 was driven by both a reduction in incidence and improved survival, particularly from targeted therapies. The findings highlight the importance of incidence-based mortality methods in evaluating subtype-specific mortality trends and the potential impact of new treatments and screening programs.This study examines the impact of advancements in lung-cancer treatment on population mortality, focusing on the distinct subtypes of non–small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). Using data from the Surveillance, Epidemiology, and End Results (SEER) program, the researchers assessed lung-cancer mortality and linked deaths from lung cancer to incident cases in SEER cancer registries. This allowed them to evaluate population-level mortality trends attributed to specific subtypes, known as incidence-based mortality. The results showed that mortality from NSCLC decreased more rapidly than incidence, primarily due to improvements in survival over time, which were associated with the approval and use of targeted therapies. For example, among men, incidence-based mortality from NSCLC decreased by 6.3% annually from 2013 to 2016, while the incidence decreased by 3.1% annually from 2008 to 2016. Lung cancer-specific survival improved from 26% among men with NSCLC diagnosed in 2001 to 35% among those diagnosed in 2014. Similar patterns were observed among women with NSCLC. In contrast, mortality from SCLC declined mainly due to a decrease in incidence, with no significant improvement in survival. The study concludes that the sharp decline in population-level mortality from NSCLC in the United States from 2013 to 2016 was driven by both a reduction in incidence and improved survival, particularly from targeted therapies. The findings highlight the importance of incidence-based mortality methods in evaluating subtype-specific mortality trends and the potential impact of new treatments and screening programs.