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# FDA Harmonizing MDR Adverse Event Coding with Other Regulators
- URL: https://www.fdaweb.com/fda-harmonizing-mdr-adverse-event-coding-with-other-regulators/
- Published: 2017-11-10T12:00:00.000Z
- Updated: 2026-09-14T23:01:14.000Z
- Author: David McFarland
- Tags: Devices, #legacy-id-D5140109

FDA says it is no longer adding new adverse event codes for Medical Device Reporting (MDR) in response to device manufacturer requests. As part of an adverse event harmonization effort with the International Medical Device Regulators Forum (IMDRF), FDA expects to transition to the new coding as new annexes from the group are published. Manufacturers and other stakeholders who would like to request that a new adverse event code be added should follow the [IMDRF code request process](http://www.imdrf.org/workitems/wi-aet-maintenance.asp?ref=fdaweb.com).

The IMDRF Adverse Event Reporting terminologies [working group](http://imdrf.org/workitems/wi-aet.asp?ref=fdaweb.com) is iteratively producing new code sets, which are posted to the [IMDRF documents repository](http://imdrf.org/documents/documents.asp?ref=fdaweb.com) as new annexes on a singular guideline document. “As each new annex is published, FDA intends to update the corresponding FDA code set to harmonize with the new IMDRF code set; as a result, each IMDRF code will map to a single, distinct FDA code,” an FDA [notice ](https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/PostmarketRequirements/ReportingAdverseEvents/MDRAdverseEventCodes/default.htm?ref=fdaweb.com)says. “At this time, the FDA’s eMDR system is not configured to accept the IMDRF codes, however, once the IMDRF working group has published the initial version of all IMDRF code sets, the FDA plans to update eMDR to accept IMDRF codes, in addition to the FDA codes and NCIt \[NCI Thesaurus\] codes that are currently accepted. This will be possible because all three (FDA, NCIt, and IMDRF) coding systems will be harmonized with a one-to-one mapping for each code across all three systems.”