Key PointsQuestionDoes the national prevalence of nicotine dependence vary by year, age, psychiatric comorbidities (substance use disorder and/or depression), and sociodemographic characteristics?FindingsIn this cross-sectional study of 152 354 US community-dwelling adults with past-month cigarette use, the adjusted prevalence of nicotine dependence decreased from 59.52% in 2006 to 56.00% in 2019 among adults with past-month cigarette smoking and among each age group, except for ages 18 to 25 years. Adults 50 years and older (especially those with substance use disorder and/or depression) had the highest prevalence of nicotine dependence.MeaningThese findings suggest that evidence-based tobacco cessation strategies tailored to age and psychiatric comorbidities are needed.