Verify Code Existence

This transaction allows a PoS, or any OHIE component, to access terminological information in the terminology service to verify that a code exists. A typical example would be to validate that the codes contained in an incoming patient data message are, in fact, from a required code system, e.g. ICD-10 or LOINC.

Both external systems and systems inside the HIE may perform this transaction directly with the TS. The sequence diagram below shows the steps that occur for a system using this transaction.

  1. Existence: Is a Concept Code present in a specified Code System. E,g., is '123XYZ' a valid Code in the ICD-10 Code System?

Workflow Maturity


  • One or more OpenHIE implementations of this workflow exist in one or more countries

  • Workflow is defined and ARB approved

  • Workflow is supported by mature standards


The FHIR CodeSystem validate-code operation: HL7 FHIR Specifications v3.0 or higher support validate-code. The response is a Boolean (true or false) based on whether the code exists in the specified CodeSystem.

This workflow implements the IHE IT Infrastructure Technical Framework Supplement - Sharing Valuesets, Codes, and Maps (SVCM) Transaction: Validate Code ITI-Y5 for Code Systems.

Assumptions and Prerequisites

The required CodeSystems have been preloaded into the Terminology Service.


  • PoS - The point-of-service system or other HIE component that is requesting to verify a code.

  • TS - Stores the curated official version of the terminology and codes for the health system.

Interaction Description

The following is a description of the interaction steps.




Transaction Options


Code verification request

The validate-code request is triggered by a PoS or other HIE component.

Input: A Concept Code and target Code System.

FHIR CodeSystem Resource, $validate-code operation


Code verification response

The response is sent back to the requesting system. Output: a True or False response.

FHIR CodeSystem Resource, $validate-code operation

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