HL7 FHIR Implementation Guide: minimal Common Oncology Data Elements (mCODE), v0.9.0

- Local Development build (v0.9.0). See the Directory of published versions

Contents of this Implementation Guide



According to the National Cancer Institute, 38.5 percent of men and women will be diagnosed with cancer at some point during their lifetimes. In 2014, an estimated 14.7M people were living with cancer in the United States. While numbers for cancer and other major diseases are staggering in terms of human suffering, such large figures also provide a place to look for potential solutions. The ultimate goal is to establish data models, technologies, and methods that result in research-quality real-world EHR data for every patient that drives evidence-based and data-driven treatment and analytics for high-quality health outcomes. The intent is that this research-quality real-world data would allow the information gathered from all cancers patient to contribute substantially to improving care for all future cancer patients.

mCODE™ —short for Minimal Common Oncology Data Elements—is an initiative intended to assemble a core set of structured data elements for oncology electronic health records (EHRs). The goal is to facilitate cancer data interoperability and improve overall cancer data quality for patient care and research by establishing a set of elements that would form the basic data that would populate all EHRs for patients with cancer. mCODE™ has been created and is being supported by the American Society of Clinical Oncology (ASCO®) in collaboration with the MITRE Corporation. (source: ASCO)


The mCODE model consists of a core set of structured data elements necessary to support clinical care and oncology research across all cancers.

Content and organization

The implementation guide (IG) is organized into sections which support the main components relevant to understanding the mCODE model. FHIR-specific documentation outside of the FHIR profiles exists in Appendix A which focuses on technical implementation. This allows for introductory and overview content to be shared among the broader community which includes clinicians, project leaders, and executive decision makers.

The table below provides a list of the main sections in this guide and a summary of the content found in each:

A summary of the mCODE data elements.
A visual diagram illustrating the categories and relationships of the key mCODE data elements.
Example FHIR instances conforming to a specific profile demonstrating how to represent its related mCODE data elements. The examples can also be found within the profile link.



Under the leadership of ASCO and in partnership with CancerLinQ and MITRE, a committee of leading clinical experts in oncology developed two use cases which drove the initial clinical data requirements for mCODE.

  • Use Case 1: Patient diagnosis and treatment
  • Use Case 2: Patient diagnosis and treatment referencing a next generation sequencing (NGS) genomic test

A survey was conducted to prioritize an identified list of data elements from these use cases. Further scoping was done based on whether the data would be stored or capture in an electronic health record (EHR), or if it placed undue documentation burden on the clinician.



  • mCODE elements listed in this IG might vary from the list identified by ASCO in their recent survey. These elements are subject to change based on review from ASCO, CancerLinQ, and other reviewers from the oncology community.
  • Links to Argonaut IG content are not working due to limitations in the FHIR IG Publisher. The Argonaut Data Query Implementation Guide Version 1.0.0 is located here. We apologize for the inconvenience.



Domain content was provided by the ASCO/CancerLinQ team with additional research from the MITRE Corporation. Help, guidance, and wisdom was generously provided by all members of the ASCO/CancerLinQ team, especially the Dr. Robert Miller and Dr. Wendy Rubenstein.

This IG was authored by the MITRE Corporation using the Clinical Information Modeling and Profiling Language (CIMPL), a free, open source toolchain from MITRE Corporation.


Approved for Public Release. Distribution Unlimited. Case Number 16-1988

© 2019 ASCO and the MITRE Corporation on behalf of the members of the mCODE™ Executive Committee. This work is made available to the public on an open source basis under the Creative Commons 0 (CC0) license