Adult smokers (21-65) and adolescent smokers (18 - 21) years of age residing in Alameda and Santa Clara counties will serve as the target population for this study. A total of 400 smokers meeting eligibility criteria will be randomized. Treatment will include both open label and extended treatment phases. Randomization. Participants will be randomized to extended therapy or control conditions at baseline (prior to open label treatment) and the analysis will be intention-to-treat (ITT) to avoid the threat of selection bias. Primary hypothesis. Smokers randomized to receive CBT during extended treatment will have a higher prolonged abstinence rate (PA) at 52 week and 104 week follow-up than participants in the Supportive therapy Control treatment.