FHIR Mapping Language (FML)
0.1.0 - STU 1 International flag

FHIR Mapping Language (FML), published by HL7 International / FHIR Infrastructure. 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/HL7/mapping-language-ig/ and changes regularly. See the Directory of published versions

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Official URL: http://hl7.org/fhir/uv/fml/ImplementationGuide/hl7.fhir.uv.fml Version: 0.1.0
IG Standards status: Trial-use Maturity Level: 3 Computable Name: FML

Introduction

The FHIR Mapping Language specification was previously a part of the core FHIR Specification, however as of FHIR version 6.0 it has been removed into it's own Implementation Guide. This is consistent with other similar specifications like FHIRPath andCQL, which are both used intimitely with FHIR content, however are defined outside the specification, and have their own lifecycle outside the core FHIR balloting process.

This specification can be used with ANY version of fhir, and one of its primary use cases is mapping between versions of FHIR, and not just the version that the mapping language was defined for.

The content of the mapping language specification is to be considered normative with respect to the content that was included in previous versions of FHIR. Clarifications to remove ambiguity, and also additional functionality can be added to the language, however any existing maps there were conformant with the FHIR R5 FML text representation must be able to be parsed and executed with any new version.

We welcome and encourage all feedback on this content.

Cross Version Analysis

Dependency Table

IGPackageFHIRComment
.. FHIR Mapping Language (FML)hl7.fhir.uv.fml#0.1.0R6
... HL7 Terminology (THO)hl7.terminology.r5#7.2.0R5Automatically added as a dependency - all IGs depend on HL7 Terminology
.... FHIR Extensions Packhl7.fhir.uv.extensions.r5#5.3.0R5
... FHIR Tooling Extensions IGhl7.fhir.uv.tools.r5#1.1.2R5for example references

Package hl7.fhir.uv.extensions.r5#5.3.0

This IG defines the global extensions - the ones defined for everyone. These extensions are always in scope wherever FHIR is being used (built Sat, May 16, 2026 18:32+1000+10:00)

Package hl7.fhir.uv.tools.r5#1.1.2

This IG defines the extensions that the tools use internally. Some of these extensions are content that are being evaluated for elevation into the main spec, and others are tooling concerns (built Tue, Mar 24, 2026 11:13+1100+11:00)

Global Profiles Table

There are no Global profiles defined

IP Statements

No use of external IP