MedlinePlus Connect is an award-winning, free service of the National Library of Medicine (NLM) and the National Institutes of Health (NIH) that easily links patient portals and electronic health record (EHR) systems to MedlinePlus.gov, an authoritative, up-to-date health information resource for patients, families and health care providers. MedlinePlus Connect provides context-relevant responses for problems and diagnoses, medications and lab tests. MedlinePlus Connect supports the HL7 Context-Aware Knowledge Retrieval (Infobutton) standard and accepts requests containing standardized code sets already used by EHRs. It is available as a Web application and as a Web service.