LOINC Version 2.68 and RELMA Version 7.1 are now available

Download Current Versions

LOINC 2.77
Released 2024-02-27

RELMA 7.10
Released 2024-02-27


We are excited to announce that LOINC version 2.68 and RELMA version 7.1 are now available! This release contains lots of new content and feature updates. We'll cover the highlights here, and encourage you to read the LOINC Release notes and file-specific Release and Readme notes for more details about individual files.

    1. LOINC License 5.0
    2. LOINC Knowledge base
    3. The Numbers
    4. New content highlights
      1. SARS-CoV-2/COVID-19
      2. Other new content
    5. Overview of edits to existing terms
    6. LOINC FHIR Terminology Services API updates
      1. Updated LOINC content
      2. New properties
      3. Questionnaires
      4. Updated definition of LOINC as a code system resource
      5. Updated information on loinc.org/fhir
    7. RELMA version 7.1
      1. Support for Windows 7 discontinued
      2. RELMA help and manual using new LOINC KB
    8. LOINC Linguistic Variant updates
    9. Changes to other files
      1. LOINC Part file
      2. LOINC Common UCUM codes
    10. Your feedback is needed
    11. Changes for December 2020

Read on for the full details.

Highlights from the latest LOINC release

This section describes the most important changes included in the current LOINC release.

LOINC License 5.0

The new LOINC License includes several important updates. Key changes include:

  • Requiring a single, short version of the notice when LOINC is incorporated into a variety of products and services rather than having different versions depending on the product or service;
  • More flexibility in which fields must be included when LOINC is incorporated into a product or service;
  • Adding a definition of "You", "Your", and "User" to mean either an individual OR the organization specified by an individual on whose behalf the license terms and conditions are being accepted;
  • Addition of several release artifacts to the "Group 3 Artifacts" list that had not been included in prior versions of the license.
    Please review the license document to see all of the changes.

In addition, we have changed the language around accepting the license to include accepting the terms and conditions on behalf of the organization specified in an individual user's account.

LOINC Knowledge base

We are excited to announce the launch of the LOINC Knowledge base (LOINC KB)! The LOINC KB is incorporated into the LOINC website functionality and includes educational resoures that until now, were only available in PDF or other formats that were not broadly searchable. For this release, several resources have been transformed into the new format (using Gitbook, which uses Github and Markdown), for inclusion in the LOINC KB, including the LOINC Users’ Guide, RELMA Manual, Frequently Asked Questions (FAQ), Enriched Linkages between LOINC terms and LOINC Parts, and the LOINC license. We plan to keep adding to the LOINC KB, such as including all of the Release and Readme notes.

The Numbers

1231 new terms (93600 total)

  • Laboratory (Type 1): 747 new (57108 total)
  • Clinical (Type 2): 244 new (24439 total)
  • Attachments (Type 3): 0 new (1157 total)
  • Survey (Type 4): 240 new (10896 total)

318 term status changes

  • 309 TRIAL → ACTIVE

3245 term edits (See Updates file for details)

  • 219 NAM (Component update)
  • 96 MAJ (Update to one of 5 other primary axes)
  • 2870 MIN (Update to secondary field - see Updates file Readme for the full list)
  • 6 DEL (Status changed to DEPRECATED)
  • 54 PANEL (Change in the child elements or conditionality of one or more child elements in the panel or a sub-panel contained in the panel)

New content highlights


Creating LOINC terms and other resources related to SARS-CoV-2/COVID-19 testing, documentation, and reporting was our primary focus during this release cycle. We worked closely with the CDC, FDA, APHL, laboratories, IVD manufacturers, and other stakeholders to create LOINC content for SARS-CoV-2 laboratory tests, including molecular, antigen, antibody, and culture assays. We also created convalescent plasma terms, terms for case reporting and document terms related to COVID-19 and telehealth clinical notes.

We have updated SARS-CoV-2/COVID-19 content almost weekly since January, and sometimes more frequently. All of the LOINC terms related to SARS-CoV-2/COVID-19 testing can be found on a new, dedicated webpage that supports downloads of filtered subsets of these terms. This page includes both released and pre-release terms and is updated as soon as new terms or term edits are made. Note that the SARS-CoV-2/COVID-19 terms included in the 2.68 release are no longer available on the LOINC Prerelease page.

We also created a separate page to provide guidance for choosing LOINCs for SARS-CoV-2 testing, including IVD test kit-specific mappings for those manufacturers that gave us permission to list their information and general FAQs about SARS-CoV-2 and COVID-19.

Groups for SARS-CoV-2

3 Groups were created specifically for SARS-CoV-2 laboratory terms:

  1. Parent LG51014-5/Group LG51017-8 (SARSCoV2 detection) contains all LOINC terms related to detection of the SARS-CoV-2 virus, including molecular, antigen, and culture terms
  2. Parent LG51016-0/Group LG51019-4 (SARSCoV2 molecular detection) contains all LOINC terms for molecular detection of the SARS-CoV-2 virus
  3. Parent LG51015-2/Group LG51018-6 (SARSCoV2 antibody detection) contains all LOINC terms for SARS-CoV-2 serology testing

An additional value set was created to gather terms related to COVID-19 and other case reporting. This is not a Group but is represented as a FHIR ValueSet: http://loinc.org/vs/loincs-related-to-public-health-case-reporting.

The 3 Groups and value set are described on the FHIR terminology services page.

Other new content

  • New laboratory tests include:
    • 276 new microbiology terms, 62 of which report on the pandemic virus, SARS-CoV-2 (COVID-19)
    • Nearly 120 new terms in the chemistry and challenge classes
    • 115 new molecular pathology terms
    • plus new terms in blood bank, serology, allergy, coagulation, cell markers, drug/tox and more
  • New clinical terms include:
    • More than 100 new clinical document terms, most related to COVID-19 terms or telehealth notes as a result of COVID-19 quarantine
    • Almost 60 new Ophthalmology terms
    • Approximately 30 new terms for various history and physical concepts, including case reporting concepts related to new COVID-19 reporting requirements.
    • plus terms related to radiology, public health, trauma and more
  • New clinical and survey panels include:
    • Safe Environment for Every Kid parent questionnaire - revised (SEEK) (95403-2)
    • U.S. Household Food Security Survey (95246-5)
    • U.S. Household Food Security Survey - Six Item Short Form (95361-2)
    • U.S. Adult Food Security Survey (95353-9)
    • Functional Assessment Standardized Items (FASI) - version 1.0 (94848-9)
    • Patient Health Questionnaire 8 item (94329-0)
  • Patient Reported Outcomes Measurement Information System (PROMIS) panels:
    • PROMIS Pediatric - Global Health 7 - version 1.0 (94257-3)
    • PROMIS Parent Proxy Global Health 7 - version 1.0 (94165-8)
    • PROMIS Parent Proxy Short Form - Pain Interference 8 - version 1.0 (94180-7)
    • PROMIS Parent Proxy Short Form - Physical Function - Upper Extemity 8 - version 1.0 (94169-0)
    • PROMIS Parent Proxy Short Form - Mobility 8 - version 1.0 (94166-6)
    • PROMIS Parent Proxy Item Bank - Pain Interference - version 1.0 (94162-5)
    • PROMIS Pare Proxy Item Bank - Mobility - version 1.0 (94161-7)
  • Phenotypes and exposures (PhenX) panels:
    • PhenX - Use of creatine growth hormone and steroids protocol 230801 (94451-2)
    • PhenX - Human Papillomavirus Vaccine Use Protocol 100802 (94327-4)
    • PhenX - Ethnicity Protocol 010502 (94158-3)
    • PhenX - Age of Initiation of First Cigarette Use - Adult Protocol 030703 (94157-5)
  • Ophthalmology Lensmeter panel (95318-2)
  • Ophthalmology Keratometry panel (95298-6)
  • Columbia - Suicide Severity Rating Scales (C-SSRS) and screener 93245-9">93245-9, 93373-9">93373-9, 93485-1">93485-1

Edits to existing terms

Changes based on internal review or as part of an ongoing project include:

  • Updated several terms in the PHENX Class and moved them to a more representative Class
  • Updated "Viral hemorrhagic disease virus" to "Rabbit hemorrhagic disease virus" based on the short name, which includes the RHDV acronym, and to align with the species name used in the International Committee on Taxonomy of Viruses (ICTV). Separate terms exist in LOINC for other hemorrhagic disease virus testing
  • Nominal KEL, RHD and RHCE (Rh blood group) gene targeted mutation analysis terms as well as CYP* and UGT1A1 gene target mutation analysis terms, all currently used across labs to report allelic genotypes, were updated to the current LOINC model for genotype reporting, which was the original intent for such terms
  • Updated many Ophthalmology terms by moving LM (Lensmeter) from the System to the Method for accuracy and converting the Method "Ophthalmometer" to "Keratometry" to align with current terminology. Additionally, some cornea and retina terms that previously had the System: Eye, were updated to Cornea and Retina for precision
  • Adjusted naming of several vitamin D terms for internal consistency
  • Changed System from XXX to ^Specimen for for a number of terms related to specimen collection

Changes based on community input include:

  • Updated several panels by adding additional child elements and making the required/optional/conditional values less restrictive (to find these filter on CHNG_TYP:Panel and VersionLastchanged:268 in the LOINC Table)
  • Updated multiple Display Names for consistency
  • Corrected the example UCUM units for several hundred terms with the Property ACnc that previously included U, which is reserved for catalytic units, to include [arb'U]. For example, U/mL was corrected to [arb'U]/mL. In addition, a unit for the volume divisor was added to ACnc terms that previously did not include a divisor unit in the example UCUM units
  • Corrected the example units for several hundred terms with the Property ACnc that previously included U, which is reserved for catalytic units, to include arb U. For example, U/mL was corrected to arb U/mL
  • Updated the Status from TRIAL to ACTIVE for terms contained within the collection of Centers for Disease Control (CDC) Public Health Emergency Operations Center (PH EOC) minimum data set (MDS) (89724-9)

What's new with the LOINC FHIR Terminology Services (TS) API

FHIR R4 is here!

Updated LOINC content available through the API

During our release process we have updated our FHIR terminology server with the latest content. The server currently supports CodeSystem, ValueSet, ConceptMap, and Questionnaire resources.

New Properties

Display names

You can now access the Display Names, which were promoted to production in the December 2019 release, with the DisplayName property.

DetailedModel and SyntaxEnhancement properties

We expanded the LOINC-specific properties available in our FHIR representation to include those that are published in the LoincPartLink_Supplementary file, which is available in the Part download file. For more information about these properties, please see the documentation included with the Part file.


A categorization such as general clinical domain, service area, or other grouping useful for indexing,searching, or grouping for display (e.g. Cardiology, Neurology, Laboratory, etc). These categories utilize existing LOINC CLASS Parts and are assigned to LOINC terms both programmatically and manually. See the Part file Readme and Release notes and FHIR’s category element for Observation, DiagnosticReport, and DocumentReference for more information and examples.


In the previous release, we had implemented the Argonaut Questionnaire Profile. For this release, with the upgrade to R4, we updated our questionnaire implementation based on the R4 Questionnaire resource. As part of this, we added panel attributes, such as text-based skip logic, form context, and form coding instructions, in a format supported by the Questionnaire resource. Note that this is a work in progress, and we would welcome feedback.

Updated definition of LOINC as a code system resource

We have updated the canonical definition of LOINC as a CodeSystem resource to include the latest enhancements. LOINC's CodeSystem definition is available for download at https://loinc.org/fhir/loinc.xml.

Find more information about LOINC's FHIR TS at https://loinc.org/fhir

RELMA version 7.1

Windows 7 no longer supported

Microsoft officially ended support for Windows 7 in January 2020. Therefore, RELMA is no longer supported on this platform. RELMA is only officially tested and validated on the Windows 10 operating system.

RELMA documentation and help system is part of the new LOINC KB

The RELMA documentation and help system have been moved to the new LOINC KB described above. You can still access help through the application. However, you can also access it directly at https://loinc.org/kb/relma. We are also still providing the user manual as a .pdf that is installed with the application.

LOINC Linguistic Updates

The global community of LOINC users continues to help produce a wonderful collection of translations. These linguistic variants (we support multiple translations of the same language) are available in RELMA, the online search.loinc.org application, and in the LOINC Linguistic Variants File.

Updated Linguistic Variants in this release:

  • nl_NL_22 - Dutch (NETHERLANDS)
  • fr_CA_8 - French (CANADA)
  • de_DE_15 German (GERMANY)
  • zh_CN_5 - Chinese (CHINA)
  • it_IT_16 Italian (ITALY)

CUMUL translations retired

The linguistic variants listed below were retired because the translation effort that produced them was suspended many years ago, and more comprehensive translations for each language have been produced by others. The notice that we would be retiring these was originally published with LOINC release 2.64.

  • German (SWITZERLAND)
  • French (SWITZERLAND)
  • Italian (SWITZERLAND)
  • Spanish (SWITZERLAND).

Key changes to existing LOINC release artifacts

LOINC Part File

This file has been incremented to 5.0, Alpha because we split the original LoincPartLink.csv file into 2 separate files:

  • LoincPartLink_Primary.csv - This file contains the Primary, Radiology, and Document Ontology parts.
  • LoincPartLink_Supplementary.csv - This file contains all the other LOINC part relationships other than Primary, Radiology, and Document Ontology.

We split the file for two reasons: one, the original file was extremely big, and two, we think it is important to clearly identify the most important (i.e., Primary, DocumentOntology, and Radiology) attributes that should be implemented for each term. Note that the supplementary file still exceeds the row capacity of Excel and LibreOfficeOne.

This release remains at Alpha pre-production status because we are continuing to evaluate our approach to linking LOINC Terms to Parts in these files, including for suffixes, divisors, and core components versus full components, and before incrementing the maturity level for this file, we would like further testing and feedback about these approaches and the file structure.

LoincPartLink_Supplementary.csv exceeds the row capacity of Excel and LibreOffice. Please be aware of this fact when using this file.

Please see the extended documentation, Release Notes, and Readme contained in this artifact for detailed reference information about this powerful resource and the ideas noted for future work. We welcome user feedback on these ideas, especially about linkages to external coding systems, the addition of category links to enable the use of LOINC Parts for organizing terms across Classes, and the format/size of the LoincPartLink_Supplementary.csv.

LOINC Common UCUM Codes

For this release, nearly 40 codes were added to the LOINC Common UCUM Codes file that are present in the LOINC table as example UCUM units for at least 10 terms each. We plan to do a closer review of this file and its contents for the next release.

Your feedback is needed for promoting these artifacts!

LOINC Change Snapshot File

The purpose of the LOINC Change Snapshot File is to provide a structured record of the key changes to LOINC content that occurred in this release. In this second Alpha release, we continue to only include LOINC Terms and Parts that have had a change in their Status since the last release (new LOINC terms are not included because they did not exist and therefore did not have a Status in the last release). There are separate .csv files for changes to LOINC terms and LOINC Parts.

Design notes and request for comment

In these files, we purposefully used the Property field to carry the identification of the attribute of the LOINC Term or Part that changed. This use of Property is the same meaning as in our FHIR CodeSystem representation, and not that of Property in the LOINC Fully Specified Name.

Within our internal LOINC management system, we are now tracking "change reasons" at the more detailed field level as described above. Therefore, we are able to report these field-level changes in separate rows of the Change Snapshot file rather than, or in addition to, the CHANGE_REASON_PUBLIC field in the LOINC table.

We would like user feedback on,

  • whether this file is useful in its current state,
  • whether we should make any changes either in terms of structure, the fields or attributes whose changes should be included in the file, or
  • if new .csv files should be added to reflect key changes in other artifacts, such as the LOINC PanelsAndForms or Answer Files.

LOINC Consumer Name File

We have continued to refine our new Consumer Names, which are available for all Laboratory LOINC terms and a subset of Clinical LOINC terms. The ConsumerName is created algorithmically, based on manually crafted labels (names) for each Part. These names do not represent each of the defining Parts of a given term, are not unique, and do not include an indicator that a term is deprecated.

We welcome your feedback about these names and expect to make iterative refinements to the approach over time.

The LOINC Consumer Names are intended for downstream display only and are not intended to be used at any point in the clinical workflow, nor for the purpose of mapping local terms to LOINC.

LOINC Group File

We are still looking for feedback about whether LOINC Groups are useful in their current state or whether there are changes, either in terms of content or structure, that would improve their usability. This feedback is especially important for the new SARS-CoV-2 Groups (see information under New content highlights above). If you are using LOINC Groups, please drop us a note to tell us so that we can decide whether we should continue maintaining, publishing, and enhancing them.

LOINC Multiaxial Hierarchy File

In this release of the Multiaxial Hierarchy we continued to enhance the clinical LOINC hierarchy by adding more clinical Component Parts to the Component hierarchy. This change results in the LOINC terms using these Components being in a specific node in the hierarchy rather than in the ClinicalNotYetCategorized node. Two areas that we targeted for this release were vital signs and body measurements.

We continue to seek user feedback about our changes to the hierarchy, and especially about the approach to including the Class in the construction of the hierarchy nodes.

Notice of changes to the public LOINC data files for the December 2020 Release


Notice of upcoming changes to this artifact in the December 2020 release:

Field Name: SPECIES
Formal Definition: Codes detailing which non-human species the term applies to. If blank, "human" is assumed.
Action: DELETE

This field has not been updated in many years. The values stored in the field are non-standard codes that are inconsistent in meaning and format. We decided that it would be better to eliminate the field rather than provide incomplete or confusing information. For this release we have emptied the field in preparation for deleting it from the database in the December 2020 release.

Thank you for your support!

Thank you to the LOINC team for all of your exceptional work in putting this release together in the midst of the COVID-19 pandemic.