We developed a theory-driven interactive Patient Health Record (PHR) that uses higher functionality to more deeply engage patients in health promotion. The model defines five levels of PHR functionality: (1) collecting patient information, (2) integrating with electronic health records (EHRs), (3) translating information into lay language, (4) providing individualized, guideline-based clinical recommendations, and (5) facilitating patient action. We hypothesize that implementing PHRs with these higher levels of functionality will inform and activate patients in ways that simpler PHRs cannot achieve and will increase uptake of preventive services. In Phase 1, we will randomize 46 practices from three practice-based research networks in eight states to implement a PHR with advanced versus simpler functionality. Control practices will use their existing PHR. Intervention practices will upgrade their PHR to feature an interactive preventive health record (IPHR) that we have previously developed and tested. Intervention practices will locally tailor the IPHR content and learn how to integrate new functions into practice. Phase 1 will feature an implementation assessment in intervention practices, based on the RE-AIM model, to measure Reach (creation of IPHR accounts by patients), Adoption (practice decision to use the IPHR), Implementation (consistency, fidelity, barriers, and facilitators of use), and Maintenance (sustained use). The randomized comparison of intervention and control practices will measure the incremental effect of the IPHR on shared decision-making and receipt of cancer screening tests compared to traditional PHRs (Effectiveness). Data sources will include the EHR/PHR/IPHR databases, patient and practice surveys, recruitment field notes, practice learning collaborative transcripts, practice diaries, and patient phone interviews. This study will inform future efforts to use patient-centered information technology to promote cancer prevention and the feasibility of national dissemination.