HL7 v2.5.1 Vocabulary
0.1.0 - ci-build

HL7 v2.5.1 Vocabulary, published by HL7/FO. This guide is not an authorized publication; it is the continuous build for version 0.1.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/frankoemig/hl7.v2.terminology.v251/ and changes regularly. See the Directory of published versions

## CodeSystem: Match Reason (2.5.1 - 1.0.0) (Experimental)

Official URL: http://terminology.hl7.org/v2plusvocab/CodeSystem/matchReason | Version: 1.0.0
Active as of 2026-01-27 | Computable Name: MatchReason
Other Identifiers: OID:2.16.840.1.113883.18.243
Copyright/Legal: HL7 Inc., 2026

Code system of concepts identifying what search components (e.g., name, birthdate, social security number) of the record returned matched the original query where the responding system does not assign numeric match weights or confidence levels. It provides a method for passing a descriptive indication of the reason a particular record was found. Used in HL7 Version 2.x messaging in the Query Response Instance (QRI) segment.

This Code system is referenced in the content logical definition of the following value sets:

- Hl7VSmatchReason

Properties

This code system defines the following properties for its concepts

Name | Code | URI | Type | Description
versionIntroduced | versionIntroduced | http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#versionIntroduced | string | version when was this code introduced
versionDeprecated | versionDeprecated | http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#versionDeprecated | string | version when was this code deprecated
status | status | http://hl7.org/fhir/concept-properties#status | code | A code that indicates the status of the concept. Typical values are active, experimental, deprecated, and retired
comment | comment | http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#comment | string | A string that provides additional detail pertinent to the use or understanding of the concept
usage | usage | http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#usage | string | usage notes for this code
modified | modified | http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#modified | dateTime | date of last modification

Concepts

This case-sensitive code system `http://terminology.hl7.org/v2plusvocab/CodeSystem/matchReason` defines the following codes:

Code | Display | Definition | versionIntroduced
DB | Match on Date of Birth | Match on Date of Birth | 2.4
NA | Match on Name (Alpha Match) | Match on Name (Alpha Match) | 2.4
NP | Match on Name (Phonetic Match) | Match on Name (Phonetic Match) | 2.4
SS | Match on Social Security Number | Match on Social Security Number | 2.4