Logical Observation Identifiers Names and Codes (LOINC) is a database and universal standard for identifying medical laboratory observations. First developed in 1994, it was created and is maintained by the Regenstrief Institute, a US nonprofit medical research organization. LOINC was created in response to the demand for an electronic database for clinical care and management and is publicly available at no cost. It is endorsed by the American Clinical Laboratory Association and the College of American Pathologists. Since its inception, the database has expanded to include not just medical laboratory code names but also nursing diagnosis, nursing interventions, outcomes classification, and patient care data sets.