Psychosocial therapies for methamphetamine (MA) addiction all have limited effectiveness, and patients treated for MA dependence have a high rate of relapse. Additionally, there are no currently approved medications for MA dependence. Thus, a significant need exists for add-on therapy for treatment of MA addiction. CBT-based text messaging could serve as a real-time intervention when craving and risk of MA use are high and patients are not in the clinic. It could further serve to reinforce CBT group therapy. If found efficacious, fully-automated CBT-based text messaging would be a relatively inexpensive adjunctive therapy that could be readily scaled up for use in a large number of patients. Additionally, this type of text messaging intervention also could be tailored to individual users, which may enhance its efficacy. This Phase I randomized crossover study will evaluate the feasibility and preliminary efficacy of CBT-based text messages in conjunction with CBT group therapy delivered over a 22-day period in MA users in the San Francisco Bay Area.