Release 4

FHIR Infrastructure Work GroupMaturity Level: N/AStandards Status: Informative

For background to this version history, see FHIR Version Management Policy.

Major Milestones:

Dec 27, 2018 4.0.1 Release 4 (1st Normative Content + Trial Use Developments)
Feb 21, 2017 3.0.1 Release 3 (STU - Standard for Trial Use)
Oct 24, 2015 1.0.2 DSTU2 (Second Draft Standard for Trial Use)
Sept 30, 2014 0.0.82 DSTU1 (First Draft Standard for Trial Use)

This is the 4th milestone release of FHIR. The only changes tracked here are the changes made after the publication of the first DSTU release. For earlier changes, see the DSTU #1 Version History . Note that a full archive history of everything is available through the HL7 GitHub archives .

Version Changes

Technical Corrections to R4: Oct-30, 2019. Corrections to invariants & generated conformance resources, and add ANSI Normative Status Notes

This list of changes is farily long for a technical correction. The first set of changes should be reviewed for impact on implementations.

Corrections to the specification - resolving internal conflicts, or correcting definitional errors:

  • Add Meta as a Special Type for Open Type Element list, allowing it to be used as a Parameter in Parameters.parameter, and in other places. The $meta operations required their use, but the design did not allow for this. [Task ]
  • Change all code system OIDs to use the root 2.16.840.1.113883.4.642.4. instead of 2.16.840.1.113883.4.642.1. due to reassigning OID leaf values without updating the root in the past. This was causing problems for OID based terminology systems [Source ]
  • Add new FHIRPath context variable %rootResource, and use it in ref-1 constraint - FHIRPath engines will need to support the new context variable [Task ]
  • Fix genomics canonical URLS: ->, ->, and -> - these are now corrected back to what they had said in R3 [Task ]
  • Fix Binding for - it had a reference to the administrative gender value set, but it wrongly referred to the one on; corrected to reference the one in the specification [Task ]

Changes to Constraints and generated definitions (fixing problems in validation, no impact on implementations, except for code generators):

Documentation Corrections and Clarifications (no implementer impact):

This technical correction also includes earlier changes made without releasing a new version:


R4: Dec 27, 2018. First Normative content, with many significant changes

Note that between R3 and R4, nearly 3000 change proposals were applied to the specification, including >1000 substantive changes, of which 339 were labeled 'non-compatible'. As such, providing a comprehensive list of changes between specifications is not appropriate. To help see and understand the differences between the specification releases, implementers can:

To help implementers, the more significant changes are listed here:

3.6.0 Current build after 3.5.0 release

Release R4 Ballot #1: Sept 20, 2018. R4 ballot #2

Major changes from R4 Ballot 1 (3.3.0):

Description Committee + Tasks Pages
All Ballots
Change the canonical URL for all v2 and v3 CodeSystems and ValueSets (and some FHIR ones too), to (from the Unified Terminology Process) Breaking change!
(no task: Vocab committee decision) todo
Normative / Infrastructure
Added reference.typeFHIR-I: GF#13543 References between Resources ΔB
Clarify definition of is-modifier + impacts on modifier extensions. Note: this lead to breaking changes
on a few extensions (changed from modifierExtension to normal extension)
FHIR-I: GF#16188 Conformance Rules ΔB, Extensibility ΔB
Add mode parameter to /metadata FHIR-I: GF#14444 RESTful API ΔB
Enhance/extend rules around changes between versionsFHIR-I: GF#13089 Version Management Policy ΔB
Add fhirVersion parameter to application/fhir mime type FHIR-I: GF#16165 RESTful API ΔB
Add the $versions operationFHIR-I: GF#17009 Capability Statement Operations ΔB
Allow exponential form for decimals (with corresponding consequences for precision) FHIR-I: GF#16874 Data Types ΔB, XML ΔB
Describe use of exponential form when searching numbers (+ clarifications for precision) FHIR-I: GF#16369 Search ΔB
Remove support for operations on historical resources Breaking change! FHIR-I: GF#17258 Operations ΔB
Change Money Type to make it simpler Breaking change! FHIR-I: GF#16297 Data Types ΔB
Change ElementDefinition.binding.valueSet to only be of type canonical Breaking change! FHIR-I: GF#16055 Element Definition ΔB
Remove restriction on Bundle containing multiple versions of the same resource Breaking change! FHIR-I: GF#17085 Bundle ΔB
Rename Binary.content to and exclude it from summary (which makes it optional) Breaking change! FHIR-I: GF#16998 , GF#16898 Binary Resource ΔB
Normative / Conformance + Terminology
Remove ValueSet.$expand profile parameter, and add parameters from ExpansionProfile Breaking change! Vocab: GF#16337 & GF#16490 ValueSet.$expand ΔB
Remove ValueSet.$expand.limitedExpansion parameter, and document how to use count instead Breaking change! Vocab: GF#16449 ValueSet $expand operation ΔB
Move Valueset.extensible to an extension Vocab: GF#16427 ValueSet ΔB
Add CapabilityStatement.implementation.custodian FHIR-I: GF#16342 CapabilityStatement ΔB
Add CapabilityStatement.imports FHIR-I: GF#14299 CapabilityStatement ΔB
Normative / Observation
Update definition of subject and add note safety page the focus element OO: GF#16136 Observation ΔB
Changed cardinality of Observation.interpretation and
Observation.component.interpretation from 0..1 to 0..*
OO: GF#16231 Observation ΔB
Changed Observation.context to Observation.encounter with type Reference(Encounter). Breaking change! OO: GF#17661 Observation ΔB

This is only the major changes. More comprehensive lists can be found in the ballot introduction (later removed).

Major changes in the other parts of the specification:

3.4.0 Current build after 3.3.0 release

Release R4 Ballot #1: Apr 3, 2018. R4 ballot #1. Major changes from R3:


Release R4 Draft: Dec 21, 2017. R4 draft ballot. Major changes:

3.1.0 R4 development begins

Release 3: Mar 21, 2017. STU3

This is the full FHIR Release 3 (R3). R3 is a complete overhaul of the specification from R2, with over 2400 change proposals process, and applied in R3. Of those changes, 380+ are labeled as a breaking change. Given this level of change, there is no useful way to present a single change list. Users can use the R2/R3 difference comparison, the R2 <-> R3 transforms, or the "Compare to R2" link at the foot of every page to help visualise the differences between R2 and R3.

Many of the changes made in this release (since 1.8.0) are in response to Quality Assurance processes in HL7, with a goal of readying the specification for Normative processes in R4:

Roll up: Of all the many changes (thousands) between R2 and R3, these are the most significant:


FHIR Rolling Build, 2016 Dec onwards


FHIR QA Release, Dec 6, 2016

STU 3 Candidate, and also the basis for several implementation guide ballots and the San Antonio Jan 2017 Connectathon

Breaking Changes Summary:

These are only the more significant changes, there were many 100s of changes made in response to ballot comments and ongoing implementation experience. These include breaking changes to may resources. Structural changes are summarized here, and Transforms between DSTU 2 and STU 3 are provided for many resources.


FHIR STU3 ballot, Aug 11, 2016

STU 3 ballot version, and also the basis for the Baltimore Sept 2016 Connectathon

Publication Changes:

  • Move the US Realm implementation guides out of the specification (see )
  • Rework the home page, and introduce modules as a way to navigate the specification + add significant new implementer advice (e.g. "Getting Started")
  • Change the Navigation menu to focus on indexes to the content in the specification
  • Move FHIRPath expression language to its long term home

Technical Changes:

  • RESTful API
    • Change the FHIR mime type to application/fhir+xml|json instead of application/xml|json+fhir (breaking change, for conformance to W3C+IETF rules)
    • Add new uses for the Prefer header (return OperationOutcome, and manage behavior related to unknown / unsupported search parameters
    • Deprecate use of the OPTIONS command to retrieve the CapabilityStatement
    • Add support for conditional references to the transaction interaction
    • Add reverse chaining
  • Formats: No change to XML + JSON formats. Add Turtle Format, and related validation tools
  • For Data Types and Resources, there is formal difference analysis from DSTU2 (also found throughout the specification), and transforms between DSTU 2 and STU 3 are provided for many resources

FHIR Current Build Update, July 8 2016

Update current version to 1.5 to prevent confusion with implementations still running the May 2016 version.

  • There are many changes in this version from 1.4.0, but no formal list is provided. A formal list will be provided for 1.6 (as a diff to 1.4)

FHIR Connectathon 12 Snapshot, Mar 30 2016

Frozen base for Connectathon 12 & For Comment ballots:


FHIR Connectathon 11 Snapshot, Dec 11 2015

Frozen base for Connectathon 11:

  • Remove GuidanceRequest
  • Add new draft resources: MolecularSequence, ExpansionProfile
  • Modifications to Financial Resource & TestScript resource

Note: this version is temporary, and was removed after Connectathon 11 was complete


GAO Ballot + technical corrections, Dec 2 2015

A ballot publication for the GAO Ballot that also includes:

  • Various technical corrections to the generated snapshots
  • Populate FHIRPath expressions in extensions for all search parameters and invariants
  • Add new draft resources: GuidanceRequest, GuidanceResponse, ModuleMetadata, ModuleDefinition, Library, DecisionSupportServiceModule, DecisionSupportRule, OrderSet, Measure
  • Major restructure of Questionnaire

Technical Correction 1, Oct 24 2015

A series of technical corrections to the specification following extensive review:

  • Corrections to Extension cardinalities in implementation guides
  • Corrections in the conformance resources that support the specifications
  • Correct several erroneous invariants
  • Various typos, broken links, and fixes in examples
  • For a comprehensive list of corrections, see the Task list for FHIR DSTU2 Technical Correction 1

DSTU 2, Sept 23 2015

Changes of significance during the QA process:

  • Remove the Clinical Quality Improvement Framework (CQIF) from this published version
  • made fixes to generated schematrons
  • updated generated comformance resources (StructureDefinitions and SearchParameters) so they were consistent with the specification
  • Many spelling / grammar / broken link fixes

DSTU 2 QA Preview, Aug 31 2015

This version had extensive change as a result of the May 2015 DSTU ballot, ongoing testing, and the open change proposals (1317 tasks). The extent of the changes is best illustrated by the number of the list of changes labeled 'breaking change' - 158 changes of 1317 total tasks. Below is a list of the most important changes:


DSTU Ballot, May 2015

This version had extensive change as a result of the January 2015 Draft ballot, ongoing testing, and the open change proposals (over 800 tasks). The list below is a summary of the major changes to resource content. It shows only a limited number of the overall changes.


  • All spaces removed
  • Extensive content changes not noted here

New Data Types

Changed Data Types

  • Coding - remove valueSet property
  • Attachment - add creation
  • Identifier - replace label with type
  • Timing - major rework of content
  • ElementDefinition - add label, code, rename 'formal' to definition, rename synonym to alias, add language to mapping, remove conformance and isExtensible and replace with strength

New Resources

Removed Resources

  • CarePlan2 -> collapsed into CarePlan
  • FamilyHistory -> broken up into FamilyMemberHistory
  • InstitutionalClaim, OralHealthClaim, PharmacyClaim, ProfessionalClaim, VisionClaim -> collapsed into Claim
  • Other - use Basic instead
  • PendedRequest,Readjudicate, Reversal, StatusRequest, StatusResponse - use ProcessRequest/Response instead
  • SupportingDocumentation - use DocumentManifest instead
  • ProcessRequest, ProcessResponse - use Task instead

Renamed Resources

  • Alert -> Flag: 'alert' made people think it was an action like an alarm
  • SecurityEvent -> AuditEvent: it wasn't just for security purposes
  • ClinicalAssessment -> ClinicalImpression: people got confused with 'assessment' tools like APGAR score
  • Profile -> StructureDefinition: 'Profile' is the process, a package of statements

Changes Inside Resources

  • Parameters - allow parameter.part to contain a resource
  • AllergyIntolerance - rename subject to patient
  • Appointment - remove lastModifiedBy/lastModified, add location
  • AppointmentResponse - remove lastModifiedBy/lastModified, add rename individual to actor
  • AuditEvent - add .event.purposeOfEvent, participant.location, .policy, and .purposeOfUse
  • Bundle - major reorganization
  • CarePlan - pull goal out + other reorganization
  • ClinicalImpression - add status, replace careplan & referral with trigger, rename diagnosis to finding, make plan 0..*,
  • Composition - change .section.content to refer to List only, not any
  • ConceptMap - change identifier to url, add useContext, change telecom to contact,
  • Condition - rename subject to patient, rename status to clinicalStatus, change to bodySite = code or Reference(BodySite), rename .codeableConcept to .code
  • Conformance (now CapabilityStatement) - change identifier to url, add useContext, change telecom to contact, add requirements and copyright, add support for conditional operations,
  • Contract - extensive rewrite
  • Coverage - add bin, subscriberId
  • DataElement (now StructureDefinition) - total rewrite to use ElementDefinition
  • Device - add status, manufactureDate
  • DeviceMetric - rename operationalState to operationalStatus, add measurementMode, rename calibrationInfo to calibration, change color to an enumerations
  • DeviceRequest/DeviceUseStatement - change to bodySite = code or Reference(BodySite)
  • DiagnosticRequest- change to bodySite = code or Reference(BodySite)
  • DiagnosticReport - add encounter
  • DocumentManifest - add options for how content is referred to
  • DocumentReference - add format, remove policyManager, make content : Attachment, and remove several related attributes, remove service reference and add context.practiceSetting, sourcePatientInfo, and related
  • Encounter - add incomingReferralRequest, allow reason to repeat, rename diet to dietPreference
  • EpisodeOfCare - rename currentStatus to status, allow referralRequest to repeat,
  • Flag - rename subject to patient, change from note to code
  • Goal - add targetDate, statusDate, author, priority
  • HealthcareService - extensive rewrite
  • ImagingObjectSelection - remove retrieveAETitle, rename retrieveUrl to url, add frames
  • ImagingStudy - add laterality, change url to attachment
  • Immunization - add encounter, rename subject to patient, rename refusedIndicator to wasNotGiven, rename refusalReason to reasonNotGiven
  • ImmunizationRecommendation - rename subject to patient
  • List - add title, status, change ordered to orderedBy, add note
  • Location - remove status
  • Media - remove created (-> Attachment)
  • Medication - add batch
  • MedicationAdministration - add reasonGiven, note, text. remove timing & maxDosePerPeriod
  • MedicationDispense - collapse to a single dispense, add daysSupply, note and substitution, change quantity to allow range
  • MedicationRequest - add note, change quantity to allow range,
  • MedicationStatement - add informationSource, status, dateAsserted, replace whenGiven with effective[x], remove device, add dosage.text
  • NamingSystem - add date, publisher,
  • NutritionOrder - extensive rewrite
  • Observation - change name to code, allow more types of value[x], change type of dataAbsentReason, change to bodySite = code or Reference(BodySite), allow identifier to repeat, add device,
  • OperationDefinition - change identifier to url, add useContext, change telecom to contact, change name to title, add reuqirements, idempotent,
  • OperationOutcome - change type of .issue.type
  • OrderResponse - rename code to orderStatus
  • Organization - remove location and contact.gender
  • Patient - communication to allow 'preferred'
  • Person - rename other to target
  • Practitioner - change type of birthDate, allow multiple roles per practitioner
  • Procedure - add status and category, change to bodySite = code or Reference(BodySite), allow date to be period too, add location, change followUp to code 0..*, add device tracking
  • ServiceRequest - change to bodySite = code or Reference(BodySite)
  • Provenance - change integritySignature to signature & make it a type, allow reference by Reference as well as URI
  • Questionnaire - add telecom
  • Schedule - move lastModified
  • SearchParameter - change telecom to contact, add status, experimental, date,
  • Slot - move lastModified
  • Specimen - change source to parent, change to bodySite = code or Reference(BodySite)
  • StructureDefinition - complete rewrite
  • Subscription - change type of tag, reanme url to endPoint,
  • ValueSet - change identifier to url, add useContext, change telecom to contact, replace purpose with useContext, add requirements, rename stableDate to lockedDate, change type of expansion.identifier, add expansion parameters

Draft For Comment, January 2015 Ballot

Breaking Changes (full list):

  • Replace atom and taglist with a native Bundle format (3728 , 3558 , 2889 ) (and also Binary)
  • JSON: change how extensions are represented (3471 )
  • RESTful API: change how version specific upgrades work (3451 )
  • DataTypes:
  • Rename Schedule to Timing (3536 , 3236 )
  • Rename Contact to ContactPoint (3533 ) and swap order of elements (3108 ))
  • Address - change zip to postCode (2888 )
  • Quantity: Correct schema spelling for "QuantityCompararator" (3531 )
  • Change allowable values for the id type to include capital letters, and allow up to 64 chars (3750 )
  • Restructure Profile - only one structure, and pull ExtensionDefinition out of Profile (3647, 3498), and pull SearchParameter out (3626 )
  • Profile: allow 0..* discriminator (3131 ), and change the way discriminators work across resource boundaries (3124 ) + generate multiple types properly (2856 )
  • remove _validate interaction, and replace with $validate operation (3686 )
  • Patient: separate birth time from birthDate (3731 ), Change Administrative Gender from a CodableConcept to a Code. Also fixed the values as male|female|other|unknown with mappings to v2 and v3 (3070 )
  • DocumentReference: change encoding of Hash to Base64 (3291 )
  • Group: rename header to title (3126 )
  • Condition: split relatedItem into two (3111 )
  • Questionnaire: drop (3255 ) and move omitReason from extension to base resource (3260 )
  • QuestionnaireResponse: allow multiple answers (3146 )
  • ValueSet: replace ValueSet.compose.include.code with ValueSet.compose.include.concept (3258 ), added new rules about expansion content (3138 )
  • Media: Rename element 'dateTime' to 'created' (3174 ) and length to duration (2866 )
  • Remove DeviceObservationReport and Query
  • Collapse AdverseReaction into AllergyIntolerance
  • Appointment changes - individual field renamed to actor, and added mappings to HL7 v2 and HL7 v3
  • FamilyMemberHistory combined with List replaces FamilyHistory (with corresponding updates to related profiles)
  • Flag replaces Alert including improved clarification of how it is used and replacement of "note" with "code"
  • CarePlan significantly refactored including splitting Goal out as a distinct resource, moving elements between activity and detail, introduction of several new elements and supported relationship types

New Resources:

New Implementation Guides (see discussion of status)

  • Renamed Namespace to NamingSystem
  • Split QuestionnaireResponse from Questionnaire and significantly revamped the Questionnaire in response to feedback from the Connectathon.
  • Added DataElement (now StructureDefinition) resource (has been previously discussed as ObservationDefinition)
  • Defined Subscription resource for evaluation
  • Add time data type
  • Define RPC-type operations on the RESTful interface, and add Operation Definition
  • Defined operations on several resources including ConceptMap, Questionnaire and ValueSet
  • Conformance (now CapabilityStatement): Change to and to, and add to point to Operation Definition
  • Profile: add Profile.url, Profile.structure.snapshot and Profile.structure.differential, and remove query definition (now in OperationDefinition)
  • Add pages for LOINC, RxNorm, and SNOMED CT
  • Significant rework for ConceptMap so it can be used to map between structures as well as value sets
  • Add Contraindication and Risk Assessment and added examples to other resources in support of these
  • Add Referral Request
  • Add supportingInformation to DiagnosticRequest
  • Add fulfills to Encounter
  • Add date and age[x] to FamilyHistory
  • Change cardinality of Location.identifier to 0..*
  • Change cardinality of Practitioner.address to 0..*
  • Add Observation.encounter to 0..*
  • Temporarily added content for the Structured Data Capture implementation guide , including profiles on several resources, conformance instances, etc. This content will be moved to an external specification once the necessary tooling is in place to support that form of publication.
  • Minor new optional elements on value set for metadata, new extensions for all the rest of the VSD project metadata, formal profile to express basic minimum metadata for value set
  • Namespace: adjustments based on Grahame's feedback

Note: a useful tool for displaying the differences between pages is the W3C HTML Diff engine .