Update QI-Core Observation references to the US Core profiles listed below and replace the existing reference to FHIR Vital Signs which is replaced by the individual US Core profile for individual vital signs rather than US Core referencing FHIR Vital Signs as with previous versions" US Core Pediatric Head Occipital-Frontal Circumference Percentile Profile US Core Blood Pressure Profile US Core BMI Profile US Core Body Height Profile US Core Body Temperature Profile US Core Body Weight Profile US Core Head Circumference Profile US Core Heart Rate Profile US Core Pediatric BMI for Age Observation Profile US Core Pediatric Weight for Height Observation Profile US Core Pulse Oximetry Profile US Core Respiratory Rate Profile US Core Smoking Status Observation Profile US Core Observation Sexual Orientation Observation Profile US Core Observation Social History Profile US Core Observation SDOH Assessment AND In the existing QI-Core Home page to avoid the need to update or re-ballot QI-Core every time a new element is required for a measure, relax the requirement that measure and CDS authors only use Must Support elements. Update the 1.12 Must Support Section:http://hl7.org/fhir/us/qicore/index.html#mustsupport-flag to state: "Artifact authors SHOULD reference only elements that are marked must support, especially in the left-hand side of artifacts (measure criteria, decision support inclusion/exclusion criteria, etc.). However, additional expectations for the data requirements of artifacts MAY be communicated via the dataRequirements elements of knowledge artifacts." In the QI-Core Profiles page, Update the QI-Core Section 2.1 Referencing QI-Core Profiles Change the SHOULDs to SHALLs: "There are a number of QI-Core profiles inherit directly from US Core profiles, if any, or other FHIR resources (i.e. USCoreImplantableDeviceProfile, FHIR VitalSigns, USCore Smoking Status etc.) and the underlying Reference elements can address the US Core or FHIR profiles for the items referenced. For any other references to base FHIR resources or those not formally defined in a QI-Core Profile, the referenced resource SHALL be a QI-Core Profile if a QI-Core Profile exists for the resource type. For example, USCore Smoking Status references US Core Patient profile, the reference to Patient SHALL be a valid QI-Core Patient." Add text, "Note to Implementers: QI-Core profiles have been developed with the principle that if the profiles only need to provide references to QI-Core Profiles, that is insufficient to require individual QI-Core profiles for all US Core profiles. There are edge cases using this approach where the FHIR validator would not validate an assumption made by the measure author, such as that an encounter traced through an observation is a QI-Core Encounter. We think that general validation of all the resources provided to the context of a measure evaluation can address that risk without the need for deriving specific profiles that only constraint reference types. We seek feedback on this point." This change will strengthen the requirement to use a QI-Core profile when using a base FHIR or US Core profile not formally defined in QI-Core to use QI-Core profiles as referenced resources if a QI-Core Profile exists for that resource.