An Electronic Health Record (EHR) is the digital system of record for a patient’s medical history, clinical encounters, diagnoses, medications, lab results, imaging, and care plans. Major EHRs in the US include Epic, Oracle Health (Cerner), athenahealth, eClinicalWorks, NextGen, and Greenway.
Patient portals typically integrate with the EHR — pulling patient-facing data (results, summaries, medications) for patient access. The EHR’s bundled patient portal (e.g., Epic MyChart) is usually the default; third-party patient communication platforms (Klara, Phreesia, Mend) layer on top via FHIR APIs.
EMR (Electronic Medical Record) is an older synonym, technically narrower but used interchangeably in practice.