The varying life-styles of narcotic addicts in Baltimore during the first decade of their addictive careers are examined with respect to the following: (1) periods of addiction, (2) transitions from addiction, (3) periods of nonaddiction. Emphasis is upon the relationship between aspects of the life-styles and the characterization of addicts according to a typology based on the concepts of opportunity and motivation to use narcotics. What emerges is a general hypothesis linking social class, associated competencies, and pattern of addiction.