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QDM - Quality Data Model

The Quality Data Model (QDM) is an information model that defines relationships between patients and clinical concepts in a standardized format to enable electronic quality performance measurement. The model is the current structure for electronically representing quality measure concepts for stakeholders involved in electronic quality measure development and reporting. Electronic health record (EHR) systems can use QDM to more consistently request, store, and convey clinical information.

The QDM is undergoing alignment with clinical decision support (CDS) standards. CMS established the QDM User Group to ensure broad stakeholder collaboration in QDM development, maintenance, and harmonization with quality measure and CDS standards to support the electronic clinical quality improvement (eCQI) landscape. Participants of this open stakeholder group use their expertise to recommend changes to the QDM based on 1) measurement needs, 2) real-world feasibility, and 3) harmonization with Health Level Seven International® (HL7) electronic clinical quality measure (eCQM) and CDS standards. You can review the QDM User Group Charter  for more information about the group. To get involved or provide feedback, refer to the Connect tab.

Find the Latest Version of the QDM

The most recent version of the QDM is QDM version 5.5 Guidance Update, published in May 2020. The Measure Authoring Tool (MAT) production version, released in the fall of 2019, uses the features and modifications published in the QDM v5.5 Guidance Update. The 2021 reporting/performance period will use eCQMs produced using QDM v5.5.

The Measure Authoring Tool (MAT) version 5.6 implemented the features and modifications from QDM v5.4 publication.  Earlier MAT versions included earlier versions of the QDM. eCQMs produced using QDM v.5.4 are for use in calendar year 2020 CMS quality reporting/performance periods. Note that the August 2018 publication of version of QDM v5.4 addresses several errata and replaced the June 2018 publication.

Visit the QDM Q&As page to review common questions and answers on QDM.

QDM Known Issues are found on the CQL Formatting and Usage Wiki.


The QDM provides the language that defines the criteria for clinical quality measurement. It allows the electronic definition of a clinical concept via its data elements and provides the vocabulary to relate these elements to each other. By relating attributes between data elements and using filtering functions, the QDM provides a method to construct complex clinical representations for eCQMs. The QDM provides the foundation for the conceptualization and specification phases in the eCQM Measure Lifecycle.

QDM Data Elements Structure

Category - Consists of a single clinical concept identified by a value set. A category is the highest level of definition for a QDM element. QDM 5.5 contains 22 categories. Some examples of categories are Medication, Procedure, Condition/Diagnosis/Problem, Communication, and Encounter.

Datatype - The context in which each category describes a part of the clinical care process. Examples of QDM datatypes include “Medication, Active” and “Medication, Administered” as applied to the QDM Medication category.

Attribute - Provides specific details about a QDM data element. QDM data elements have datatype-specific attributes. 

  • Datatype specific attributes - Datatype-specific attributes provide detail about a QDM data element based on its datatype. For example, “Medication, Dispensed”, “Medication, Order” and “Medication, Administered” all contain information about dosage, supply, frequency, and route. “Medication, Dispensed” and “Medication Order” include the attribute refills, but “Medication, Administered” does not. Because these attributes pertain to specific datatypes, they are called datatype-specific attributes. Starting with QDM version 5.5, each QDM datatype includes an actor to allow reference to the individual or organization that performed the activity. The QDM documentation provides definitions of all QDM attributes including the new actor attributes.

Entities - QDM 5.5 introduces a new concept called QDM Entities. Entities are not QDM datatypes or attributes. Use entities to represent concepts to specify details about the actor (or performer) of any QDM datatype. An eCQM can use the entities to provide further information required for an individual or organization actor to meet the measure’s criteria. Entities include Patient, Care Partner, Practitioner, and Organization. QDM 5.5 provides examples of how to use these new QDM Entities.

Connections between Standards 

eCQM Connection between Standards

Healthcare organizations receive the measure specifications, expressed in HQMF using QDM and CQL and then report results to CMS using QRDA.

Relationship to future use of Fast Healthcare Interoperability Resources® (FHIR)

For those using FHIR® resources or considering transition to FHIR for interoperability, the Quality Improvement Core (QI-Core) Implementation Guide provides mapping from QDM datatypes and attributes to QI-Core profiles and elements. The maps may assist implementers to understand the meaning of QDM datatypes and attributes.

QDM May 2019

QDM August 2018

QDM June 2017

Get Involved

The QDM User Group is a group of volunteer members who use the QDM for measure development, measure implementation, alignment with related standards, and more.

View the QDM User Group Charter and past QDM User Group Minutes for more information about the group.

If you are interested in participating in the QDM User Group, you may download the calendar appointments from the eCQI Resource Center Events page. Send an email to if you would like to be added to the QDM User Group distribution list.

Seek Help and Provide Feedback

Post technical questions and comments related to the development and implementation of QDM to the ONC Jira QDM Issue Tracker. 

Last Updated: Jun 19, 2020