A prerequisite to translating research findings into practice is information on consistency of implementation, maintenance of results, and generalization of effects. This follow-up report is one of the few experimental studies to provide such information on Internet-based health education. We present follow-up data 10 months following randomization on the "Diabetes Network (D-Net)" Internet-based self-management project, a randomized trial evaluating the incremental effects of adding (1) tailored self-management training or (2) peer support components to a basic Internet-based, information-focused comparison intervention. Participants were 320 adult type 2 diabetes patients from participating primary care offices, mean age 59 (SD = 9.2), who were relatively novice Internet users. All intervention components were consistently implemented by staff, but participant website usage decreased over time. All conditions were significantly improved from baseline on behavioral, psychosocial, and some biological outcomes; and there were few differences between conditions. Results were robust across on-line coaches, patient characteristics, and participating clinics. The basic D-Net intervention was implemented well and improvements were observed across a variety of patients, interventionists, and clinics. There were, however, difficulties in maintaining usage over time and additions of tailored self-management and peer support components generally did not significantly improve results.