---
type: "codesystem"
title: "Version Algorithm"
codesystem: "version-algorithm"
---
# Version Algorithm

- **Official URL**: http://hl7.org/fhir/version-algorithm
- **Version**: 6.0.0
- **Status**: active
- **Name**: VersionAlgorithm
- **Title**: Version Algorithm
- **Publisher**: HL7 (FHIR Project)
- **Description**: Indicates the mechanism used to compare versions to determine which is more current.
- **Case Sensitive**: true
- **Content**: complete

## Concepts

| Code | Display | Definition |
| --- | --- | --- |
| semver | SemVer | Uses the semantic versioning scheme as defined in [semver.org](http://semver.org). |
| integer | Integer | Versions are integers and ordered numerically |
| alpha | Alphabetical | Simple alphabetic sort on a case-insensitive and accent-insensitive basis.  (Sorting of different cases or accented versions of a character is indeterminate) |
| date | Date | Versions are expressed as an ISO date/time syntax (including syntaxes with only portions of a date) in the general format of YYYY-MM-DD (with or without separators). Inclusion of the time portion is optional. |
| natural | Natural | Sorted according to the algorithm defined here: [naturalordersort.org](http://www.naturalordersort.org/) |
| major-minor | Major/Minor | Similar to semver, but having only two components - i.e. a major and minor (integer) version number separated by a '.'.  The specific nature of what constitutes a major vs. minor increment is locally defined. |
| sct-url | SNOMED-CT URL | Versions are expressed according to the SNOMED URL scheme. See the [Versions](https://terminology.hl7.org/SNOMEDCT.html#versions) topic for more details. |
| us-date | US Date | Versions are expressed as an US date format, i.e. MMDDYYYY (with or without separators). |

## CodeSystem XML



```xml
<?xml version="1.0" encoding="UTF-8"?>

<CodeSystem xmlns="http://hl7.org/fhir">
  <id value="version-algorithm"/>
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
    <valueCode value="fhir"/>
  </extension>
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
    <valueCode value="normative"/>
  </extension>
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
    <valueInteger value="1"/>
  </extension>
  <url value="http://hl7.org/fhir/version-algorithm"/>
  <identifier>
    <system value="urn:ietf:rfc:3986"/>
    <value value="urn:oid:2.16.840.1.113883.4.642.4.1989"/>
  </identifier>
  <version value="6.0.0"/>
  <name value="VersionAlgorithm"/>
  <title value="Version Algorithm"/>
  <status value="active"/>
  <experimental value="false"/>
  <date value="2021-01-05T10:01:24+11:00"/>
  <publisher value="HL7 (FHIR Project)"/>
  <contact>
    <telecom>
      <system value="url"/>
      <value value="http://hl7.org/fhir"/>
    </telecom>
    <telecom>
      <system value="email"/>
      <value value="fhir@lists.hl7.org"/>
    </telecom>
  </contact>
  <description value="Indicates the mechanism used to compare versions to determine which is more current."/>
  <caseSensitive value="true"/>
  <valueSet value="http://hl7.org/fhir/ValueSet/version-algorithm"/>
  <content value="complete"/>
  <concept>
    <code value="semver"/>
    <display value="SemVer"/>
    <definition value="Uses the semantic versioning scheme as defined in [semver.org](http://semver.org)."/>
  </concept>
  <concept>
    <code value="integer"/>
    <display value="Integer"/>
    <definition value="Versions are integers and ordered numerically"/>
  </concept>
  <concept>
    <code value="alpha"/>
    <display value="Alphabetical"/>
    <definition value="Simple alphabetic sort on a case-insensitive and accent-insensitive basis.  (Sorting of different cases or accented versions of a character is indeterminate)"/>
  </concept>
  <concept>
    <code value="date"/>
    <display value="Date"/>
    <definition value="Versions are expressed as an ISO date/time syntax (including syntaxes with only portions of a date) in the general format of YYYY-MM-DD (with or without separators). Inclusion of the time portion is optional."/>
  </concept>
  <concept>
    <code value="natural"/>
    <display value="Natural"/>
    <definition value="Sorted according to the algorithm defined here: [naturalordersort.org](http://www.naturalordersort.org/)"/>
  </concept>
  <concept>
    <code value="major-minor"/>
    <display value="Major/Minor"/>
    <definition value="Similar to semver, but having only two components - i.e. a major and minor (integer) version number separated by a '.'.  The specific nature of what constitutes a major vs. minor increment is locally defined."/>
  </concept>
  <concept>
    <code value="sct-url"/>
    <display value="SNOMED-CT URL"/>
    <definition value="Versions are expressed according to the SNOMED URL scheme. See the [Versions](https://terminology.hl7.org/SNOMEDCT.html#versions) topic for more details."/>
  </concept>
  <concept>
    <code value="us-date"/>
    <display value="US Date"/>
    <definition value="Versions are expressed as an US date format, i.e. MMDDYYYY (with or without separators)."/>
  </concept>
</CodeSystem>
```