Canonical Data Model (CDM)
The Canonical Data Model (CDM) aims to standardise data structures across NHS England, facilitating data integration and interoperability.
Contents
- Documentation
About this standard
- Publisher
- NHS England
- Reference code
- DAPB4121 Amd 17/2025
- Status
- Draft in progress
Show definitions of statuses
Active. Active standards are stable, maintained and have been approved, assured or endorsed for use by qualified bodies.
Deprecated Deprecated standards are available for use and are maintained, but are being phased out, so new functionality will not be added.
Retired standards Retired standards are not being maintained or supported and should not be used.
- Standard type
- Information standards
Show definitions of standard types
Collections. A Collection is a systematic gathering of a specified selection of data or information for a particular stated purpose from existing records held within health and care systems and electronic devices.
Extractions. An extraction is a type of collection that is pulled from an operational system by the data controller and transmitted to the receiver without additional processing or transcription by the sender.
Information standards. Information standards are agreed ways of doing something, written down as a set of precise criteria so they can be used as rules, guidelines, or definitions.
Technical Standards and specifications. Technical standards and specifications specify how to make information available technically including how the data is structured and transported.
- Contact point
england.standards.assurance@nhs.net
Topics and care settings
- Topic
- Data
- Care setting
- GP / Primary care
- Hospital
- Social care
Review Information
- Scope
- All organisations that provide NHS or adult social care services are covered by the standard
- Approval date
- 3 June 2025
- Technical Committee
Data Assurance Board (https://digital.nhs.uk/data-and-information/information-standards/governance)
More information
The Canonical Data Model (CDM) aims to standardise data structures across NHS England, facilitating data integration and interoperability.
It is being developed incrementally and based on real-world use cases, and will be refined and approved through specific domains and topics. This model has been shaped by input from expert reference groups and subject matter experts and is designed to enhance the flow of data from source systems, leading to improved operational and analytical insights.
About the CDMThe model incorporates several key features and design principles to achieve its aims, ensuring data is robust, interoperable, and consistently understood:
- domain based development
- subject of care centric
- controlled vocabularies
- metadata and CDM dictionary
- technology agnostic
- normalised structure
- consolidates data standards
- alignment with key standards
- linked to NHS master and reference data
The CDM is structured in distinct layers, each building upon the last to ensure a model that is comprehensive and can be implemented.
- NHS conceptual data model
- This layer provides a high-level, technology-agnostic blueprint of fundamental healthcare concepts.
NHS logical data model (Canonical Data Model)
- NHS conceptual data model
- This technology-neutral layer defines the detailed structure and relationships of key data entities. This model represents the merger of the Federated Data Platform (FDP) and NHS logical models.
Physical data models
- NHS conceptual data model
- These models represent the actual physical implementation of the CDM, often taking the form of specific data products.
Page last updated: 22 September 2026