In mid-June, FDA published the final version of its guidance document on logical observation identifiers names and codes (LOINC) for in vitro diagnostics (IVDs).1 The guidance addresses regulatory-specific questions about the distribution of LOINC codes by IVD test manufacturers to users, primarily clinical labs and electronic health record (EHR) software vendors.

The guidance focuses exclusively on the appropriate use of LOINC codes for specific types of IVD tests and does not address coding of test results for interoperability or unique device identification.

LOINC codes describe the types of IVD tests in electronic data information systems by providing a unique numeric code, accompanied by names that specify attributes of the IVD test, such as the analyte measured, sample type, and kind of property/quantity.

With the increasing implementation of EHRs, FDA recognizes that there is a need to standardize the way IVD tests are coded. Standardizing information captured and stored in EHRs could expedite healthcare providers’ access to patient diagnostic information, reduce the laboratory burden for connecting new diagnostic systems to laboratory information systems, and facilitate the use of healthcare information for decision support tools and real-time tracking of infectious disease outbreaks.

For questions regarding the guidance document, contact the Division of Industry and Consumer Education (DICE) at FDA’s Center for Devices and Regulatory Health via [email protected], or by calling (800) 638-2041.


  1. Logical Observation Identifiers Names and Codes for In Vitro Diagnostic Test; Guidance for Industry and Food and Drug Administration Staff. Silver Spring, Md: Center for Devices and Radiological Health, FDA, 2018. Available at: Accessed June 18, 2018.