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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 measurement development and reporting. The QDM is currently being aligned with clinical decision support (CDS) standards. To ensure broad stakeholder collaboration in QDM development, maintenance, and harmonization with quality and CDS standards to support the Electronic Clinical Quality Improvement (eCQI) landscape, the QDM User Group was established. 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 7 (HL7eCQM and CDS standards. To get involved or provide feedback, refer to the Connect tab on this page.

Electronic health record systems can use QDM to more consistently request, store, and convey clinical information.

Find the current QDM

QDM v5.5 (Updated August 2019) features and modifications were implemented in the production version of the Measure Authoring Tool (MAT) released in Fall 2019. eCQMs produced using the QDM v5.5 publication will be used for the 2021 reporting/performance period.

The QDM v5.4 specification features and modifications were implemented in the Measure Authoring Tool (MAT) version 5.6 (earlier MAT versions include earlier versions of the QDM, but this current version includes only QDM 5.4). eCQMs produced using QDM v.5.4 are for use in calendar year 2020 CMS quality reporting/performance periods. Note that this version of QDM v5.4, published August 2018, addresses several errata and replaces the June 2018 publication.

The QDM v5.3 Annotated was used when creating eCQMs using Clinical Quality Language (CQL) for calendar year 2019 reporting.

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 them to each other. By relating attributes between data elements and using filtering functions, the QDM provides a method to construct complex clinical representations for electronic clinical quality measures. The QDM provides the foundation for the conceptualization and specification phases in the eCQM Measure Lifecycle.

QDM Data element 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 5.3 contains 19 categories. Some examples of categories are Medication, Procedure, Condition/Diagnosis/Problem, Communication, and Encounter.

Datatype - The context in which each category is used to describe 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 two types of attributes, datatype-specific and dataflow attributes. 

  • Datatype specific attributes - Provide specific details on a datatype, e.g., Medication, Dispensed and Medication, Ordered contain information about dosage, route, strength, and duration of a medication, while a Medication allergy, contains information about the allergy type, allergy severity, etc. 
  • Data flow attributes - Provide specific details about the location of data represented by a QDM data element e.g., Health Record Field indicates the location within an electronic record where the data should be found, Source indicates the originator of the QDM data element (an individual or a device), and a Recorder, the individual or device that enters the QDM data element into a health record field.

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.

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: Mar 25, 2020