A longitudinal analysis of 24,715 participants in the EPIC-Heidelberg cohort found that former smokers who previously met lung cancer screening criteria remain at elevated risk of lung cancer and other-cause mortality even after more than 10 years of cessation. While quitting earlier in life eliminated excess mortality risk, those who quit later—particularly after meeting screening thresholds—continued to have higher mortality than never smokers. Notably, older former smokers who were no longer eligible for screening had other-cause mortality rates similar to younger current-eligible smokers. Lung cancer risk did not decline with longer time since quitting after accounting for cumulative exposure, suggesting that cessation-based cutoffs alone may not fully capture screening-relevant risk.