Participants will be recruited from 14 VUMC-affiliate adult primary care clinics located throughout Middle Tennessee. Patients will be randomized 1:1 to the intervention or usual care. 500 adult patients with type 1 or 2 diabetes mellitus will be assigned to one of two arms. 250 will be assigned to receive access to the intervention embedded within an existing patient web portal (My Health at Vanderbilt) at Vanderbilt University Medical Center. 250 will be assigned to a usual care comparison arm with access to the currently available version of My Health at Vanderbilt without the study intervention. At enrollment, participants will complete a baseline questionnaire and diabetes health data will be abstracted from the patients' electronic health record (EHR) before being assigned to the intervention or control arm. Participants will receive additional follow-up questionnaires and diabetes health data will be abstracted from the EHR at 3-month, 6-month, and 12-month follow-ups to assess outcomes. In addition, system usage data (user analytics) will be collected throughout the study period.
