Consensus-based technical guidance for electronic case reporting (eCR) of sexually transmitted infections was implemented within existing health information technologies to automatically detect chlamydia and gonorrhea cases based on diagnosis and laboratory observation codes and build a case report using industry standards. The process was evaluated using 12 420 ambulatory encounters among adolescents and adults 15 years and older seen at 8 Chicago-area community health centers between May 1 and June 30, 2017. We tabulated the frequency of matches between the case detection logic and patient data and compared the eCR identified cases with paper case reports. This study found that eCR increased provider reporting when compared with paper reporting alone. While additional work across stakeholder groups is needed, these early findings suggest that broadly adopted eCR will decrease both provider and public health burden while improving reporting timeliness and data completion to support case investigation.