# US Quality Core Extensions - 2026 US Quality Core Implementation Guide v0.5.0

* [**Table of Contents**](toc.md)
* **US Quality Core Extensions**

## US Quality Core Extensions

This page lists the [Extensions](http://hl7.org/fhir/extensibility.html) defined as part of the US Quality Core Implementation Guide. A [registry of standard extensions](http://hl7.org/fhir/R4/extensibility-registry.html) can be found in the FHIR specification and additional extensions may be registered on the [HL7 FHIR registry](http://hl7.org/fhir/registry).

* [US Quality Core Do Not Perform Reason](StructureDefinition-us-quality-core-doNotPerformReason.md)

* [US Quality Core Diagnosis Present on Admission](StructureDefinition-us-quality-core-encounter-diagnosisPresentOnAdmission.md)

* [US Quality Core IsElective](StructureDefinition-us-quality-core-isElective.md)

* [US Quality Core Not Done Reason](StructureDefinition-us-quality-core-notDoneReason.md)

* [US Quality Core Not Done Recorded](StructureDefinition-us-quality-core-recorded.md)

* [US Quality Core USCDI+ Quality Extension](StructureDefinition-uscdiplusquality.md)

* [USQualityCore Not Done ValueSet](StructureDefinition-us-quality-core-notDoneValueSet.md)

* [USQualityCore Appropriateness Score](StructureDefinition-us-quality-core-servicerequest-appropriatenessScore.md)

