# Nature of Service/Test/Observation (2.8.1 - 1.1.0) - HL7 v2.8.1 Vocabulary v0.2.0

* [**Table of Contents**](toc.md)
* [**Artifacts Summary**](artifacts.md)
* **Nature of Service/Test/Observation (2.8.1 - 1.1.0)**

## CodeSystem: Nature of Service/Test/Observation (2.8.1 - 1.1.0) (Experimental) 

| | |
| :--- | :--- |
| *Official URL*:http://terminology.hl7.org/v2plusvocab/CodeSystem/natureOfServiceTestObservation | *Version*:1.1.0 |
| Active as of 2026-03-13 | *Computable Name*:NatureOfServiceTestObservation |
| *Other Identifiers:*OID:2.16.840.1.113883.18.90, urn:ietf:rfc:3986#Uniform Resource Identifier (URI)#http://terminology.hl7.org/v2plusvocab/CodeSystem/v2-0174 | |
| **Copyright/Legal**: HL7 Inc., 2026 | |

 
Code system of concepts specifying an identification of a test battery, an entire functional procedure or study, a single test value (observation), multiple test batteries or functional procedures as an orderable unit (profile), or a single test value (observation) calculated from other independent observations, typically used as an indicator for Master Files. Used in HL7 Version 2.x messaging in the OM1 segment. 

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

* [Hl7VSnatureOfServiceTestObservation](ValueSet-hl7VSnatureOfServiceTestObservation.md)



## Resource Content

```json
{
  "resourceType" : "CodeSystem",
  "id" : "natureOfServiceTestObservation",
  "extension" : [{
    "url" : "http://terminology.hl7.org/v2plusvocab/StructureDefinition/codesystem-v2versionCreated",
    "valueString" : "2.8.1"
  },
  {
    "url" : "http://terminology.hl7.org/v2plusvocab/StructureDefinition/codesystem-versionHistory",
    "valueString" : "generate correct history somehow"
  },
  {
    "url" : "http://terminology.hl7.org/v2plusvocab/StructureDefinition/codesystem-tableNo",
    "valueString" : "0174"
  }],
  "url" : "http://terminology.hl7.org/v2plusvocab/CodeSystem/natureOfServiceTestObservation",
  "identifier" : [{
    "system" : "urn:ietf:rfc:3986",
    "value" : "urn:oid:2.16.840.1.113883.18.90"
  },
  {
    "system" : "urn:ietf:rfc:3986",
    "value" : "http://terminology.hl7.org/v2plusvocab/CodeSystem/v2-0174"
  }],
  "version" : "1.1.0",
  "name" : "NatureOfServiceTestObservation",
  "title" : "Nature of Service/Test/Observation (2.8.1 - 1.1.0)",
  "status" : "active",
  "experimental" : true,
  "date" : "2026-03-13T11:11:38+00:00",
  "publisher" : "HL7/FO",
  "contact" : [{
    "name" : "HL7/FO",
    "telecom" : [{
      "system" : "url",
      "value" : "http://www.hl7.org"
    }]
  }],
  "description" : "Code system of concepts specifying an identification of a test battery, an entire functional procedure or study, a single test value (observation), multiple test batteries or functional procedures as an orderable unit (profile), or a single test value (observation) calculated from other independent observations, typically used as an indicator for Master Files.  Used in HL7 Version 2.x messaging in the OM1 segment.",
  "copyright" : "HL7 Inc., 2026",
  "caseSensitive" : true,
  "compositional" : false,
  "content" : "complete",
  "property" : [{
    "code" : "versionIntroduced",
    "uri" : "http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#versionIntroduced",
    "description" : "version when was this code introduced",
    "type" : "string"
  },
  {
    "code" : "versionDeprecated",
    "uri" : "http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#versionDeprecated",
    "description" : "version when was this code deprecated",
    "type" : "string"
  },
  {
    "code" : "status",
    "uri" : "http://hl7.org/fhir/concept-properties#status",
    "description" : "A code that indicates the status of the concept. Typical values are active, experimental, deprecated, and retired",
    "type" : "code"
  },
  {
    "code" : "comment",
    "uri" : "http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#comment",
    "description" : "A string that provides additional detail pertinent to the use or understanding of the concept",
    "type" : "string"
  },
  {
    "code" : "usage",
    "uri" : "http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#usage",
    "description" : "usage notes for this code",
    "type" : "string"
  },
  {
    "code" : "modified",
    "uri" : "http://terminology.hl7.org/v2plusvocab/CodeSystem/Property#modified",
    "description" : "date of last modification",
    "type" : "dateTime"
  }],
  "concept" : [{
    "code" : "A",
    "display" : "Atomic service/test/observation",
    "definition" : "Atomic service/test/observation (test code or treatment code)",
    "property" : [{
      "code" : "usage",
      "valueString" : "can be associated with one or more OM4 (specimen) segments<p>a single direct observation and would usually be associated with an OM2 and/or OM3 segments"
    },
    {
      "code" : "modified",
      "valueDateTime" : "2025-08-02"
    },
    {
      "code" : "versionIntroduced",
      "valueString" : "2.2"
    }]
  },
  {
    "code" : "C",
    "display" : "Single observation, calculated",
    "definition" : "Single observation calculated via a rule or formula from other independent observations (e.g., Alveolar-arterial ratio, cardiac output)",
    "property" : [{
      "code" : "usage",
      "valueString" : "can be associated with one or more OM4 (specimen) segments<p>a derived quantity and would usually be associated with an OM6 segment"
    },
    {
      "code" : "modified",
      "valueDateTime" : "2025-08-02"
    },
    {
      "code" : "versionIntroduced",
      "valueString" : "2.2"
    }]
  },
  {
    "code" : "F",
    "display" : "Functional procedure",
    "definition" : "Functional procedure that may consist of one or more interrelated measures (e.g., glucose tolerance test, creatinine clearance), usually done at different times and/or on different specimens",
    "property" : [{
      "code" : "usage",
      "valueString" : "can be associated with one or more OM4 (specimen) segments<p>See comment for value S"
    },
    {
      "code" : "modified",
      "valueDateTime" : "2025-08-02"
    },
    {
      "code" : "versionIntroduced",
      "valueString" : "2.2"
    }]
  },
  {
    "code" : "P",
    "display" : "Profile or battery",
    "definition" : "Profile or battery consisting of many independent atomic observations (e.g., SMA12, electrolytes), usually done at one instrument on one specimen",
    "designation" : [{
      "language" : "de",
      "value" : "Batterieanordnung"
    }],
    "property" : [{
      "code" : "usage",
      "valueString" : "can be associated with one or more OM4 (specimen) segments<p>See comment for value S"
    },
    {
      "code" : "modified",
      "valueDateTime" : "2025-08-02"
    },
    {
      "code" : "versionIntroduced",
      "valueString" : "2.2"
    }]
  },
  {
    "code" : "S",
    "display" : "Superset-a set of batteries or procedures",
    "definition" : "Superset-a set of batteries or procedures ordered under a single code unit but processed as separate batteries (e.g., routines = CBC, UA, electrolytes)<p>This set indicates that the code being described is used to order multiple service/test/observation b",
    "property" : [{
      "code" : "usage",
      "valueString" : "can be associated with one or more OM4 (specimen) segments<p>Codes P, F, and S identify sets (batteries) and should be associated with an OM5 segment that defines the list of elements.  The definitions for the contained elements would have to be sent in o"
    },
    {
      "code" : "modified",
      "valueDateTime" : "2025-08-02"
    },
    {
      "code" : "versionIntroduced",
      "valueString" : "2.2"
    }]
  }]
}

```
