Over the last two decades, HIV has transformed from an acute, deadly disease to a chronic health condition with near normal life expectancy for patients who follow optimal antiviral treatment regimens. Although this is promising news, HIV-infected individuals still face many challenges and need to be proactive in self-management of their HIV and comorbid conditions in order to live a healthy life. Personal health records (PHRs) are a key tool available to these individuals and designed to support self-management practices. In the VA, the PHR is My HealtheVet (MHV), which has approximately 2 million registered users, with HIV-infected Veterans being one of the early adopting groups. However, adoption in HIV-infected Veterans (and others with chronic disease) is still far from universal. This project will employ a multi- phase mixed methods design for in-depth analysis of My HealtheVet (MHV) use by HIV-infected Veterans and their providers. The quantitative methods will allow us to link MHV tool use to health outcomes, whereas the qualitative methods will help us achieve an understanding of why certain Veterans are adopting (or not adopting) MHV. We will also include providers, as they play a critical role in facilitating or discouraging use of MHV among Veterans. Our final aim will integrate quantitative and qualitative findings to inform the development of an intervention to increase effective use of MHV among patients and providers in ways likely to promote health; this intervention will be pilot tested in a follow-up grant. The findings of this project hold significant promise to not only improve the health of HIV-infected Veterans but others living with chronic diseases.