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Unified Medical Language System® (UMLS®)

2009AA LOINC Source Information

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The Logical Observation Identifier Names and Codes terminology (LOINC®) was developed and is maintained by the Regenstrief Institute, Inc., a non-profit medical research organization associated with Indiana University.

The purpose of LOINC is to facilitate the exchange and pooling of clinical or laboratory results for clinical care, outcomes management, claims attachment, and research by providing a set of universal codes and names. LOINC codes allow users to merge clinical results from many sources into one database for patient care, clinical research, or management.

LOINC provides formal names and standardized codes for laboratory and other clinical observations. The data cover laboratory terminology, vital signs, hemodynamics intake/output, EKG, obstetric ultrasound, cardiac echo, urologic, imaging, gastroendoscopic procedures, pulmonary ventilator management, and selected survey instruments.

Laboratory LOINC code translations are available from the Regenstrief Institute in English, Spanish, and Simplified Chinese. German, French and Italian versions are available for the 3,800 most commonly used European terms. The current French translation is from Switzerland and includes short names only.

Metathesaurus Scope
The Metathesaurus representation of LOINC also includes expanded abbreviations as well as parts data and the multi-axial hierarchy used by the Regenstrief LOINC Mapping Assistant (RELMA) tool.


LOINC users include:
  • hospitals,
  • health care systems including pediatric care systems,
  • clinical and research laboratories,
  • public health departments, including CDC,
  • electronic health record (EHR) developers, and
  • software developers.

Update Frequency
LOINC is updated twice per year.

Metathesaurus Update Frequency
LOINC is an updated source in each Metathesaurus release.

Sites Consulted

  1. LOINC® [Internet]. Indianapolis (IN): Regenstrief Institute, Inc.; c2000-2009. Logical Observation Identifiers Names and Codes (LOINC®); [cited 2009 May 22]. Available from:
  2. LOINC® [Internet]. Indianapolis (IN): Regenstrief Institute, Inc.; c2000-2009. LOINC FAQ; [cited 2009 May 22]. Available from:

Last Reviewed: February 16, 2011