Adverse Event Reporting (AER) Terminology & Codes – IMDRF Categorized Terms

This searchable directory provides standardized Adverse Event Reporting (AER) terminologies and hierarchical codes aligned with the International Medical Device Regulators Forum (IMDRF). It supports accurate global reporting, vigilance submissions, and harmonized safety classification of medical device events. Users can search by keyword or code and download results as a formatted PDF.

Terminologies for Categorized Adverse Event Reporting (AER)

Unified IMDRF device problem and event terminology (A–G). Search by keyword or code and download the results as a PDF.

Type at least 3 characters to begin searching.

🌐 Introduction

The International Medical Device Regulators Forum (IMDRF) has developed a globally harmonized terminology and coding system for adverse event reporting related to medical devices and in-vitro diagnostics (IVDs).

This unified terminology improves how safety signals are detected, analyzed, and shared among manufacturers, healthcare professionals, and regulators — ensuring faster and more reliable responses to potential device-related risks.

To support public access and understanding, IMDRF has released machine-readable JSON datasets (Annexes A–G). Our interactive IMDRF Adverse Event Code Finder fetches and displays this data directly from the official IMDRF repository in real time.

💡 Why Use IMDRF Terminology?

• Consistency: Common terminology across countries reduces confusion.
• Accuracy: Codes eliminate ambiguity in narrative reporting.
• Automation: Enables advanced data analytics and trend detection.
• Regulatory Alignment: Harmonized with FDA, ISO 19218, and GHTF standards.

For manufacturers, it simplifies multi-jurisdiction reporting.
For regulators, it enhances cross-border data exchange.
For healthcare providers and patients, it supports faster risk communication.

🧩 The Structure of IMDRF Adverse Event Terminology

The complete IMDRF terminology is divided into four main sets comprising seven annexes — each serving a specific reporting purpose.

Set	Purpose	Annex	Code Hierarchy
1. Medical Device Problem	Describe device-level malfunctions or failures	A	A|00[00][00]
2. Cause Investigation	Capture investigation details and findings	B–D	B–D|00[00][00]
3. Health Effects	Capture clinical effects and outcomes on people	E–F	E–F|00[00][00]
4. Component	Identify parts or elements involved in the event	G	G|00[000][00]

Tip: Each code has a hierarchical structure — Level 1 represents broad categories, while Level 2–3 provide detailed sub-codes.

👉 Example: A|030201 = Medical Device Problem → Mechanical Issue → Disconnection Failure

🔍 How to Use the search……

1. Enter a keyword or code (at least 3 characters) in the search bar.
2. Examples: typing “leak”, “mechanical”, or “A|01”
3. The tool automatically fetches data from the live IMDRF (Annexes A–G).
4. Results appear in a searchable table with:
   • Code (e.g., A|0302)
   • Term (e.g., “Leakage of Fluid”)
   • Description / Definition
5. Click a row to expand additional details or hierarchy context (if available).

🧠 How to Interpret Codes and Hierarchies

Schematic summary of relevant keywords with respect to adverse event terms: "term", "terminology", "code", "coding", “hierarchical coding structure" and associated "levels".

A|03 → Mechanical Problem └─ A|0302 → Leak / Leakage └─ A|030201 → Fluid Leakage

Interpretation: If an adverse event involves fluid leakage from a catheter, the best fitting term is A|030201. You can also code to a higher level (A|03 or A|0302) if details are incomplete.

⚙️ Combining Multiple Codes for Full Reporting

In practice, a complete adverse event report uses multiple terms across annexes, for example:

Category	Annex	Example Code	Meaning
Device Problem	A	A|030201	Fluid Leakage
Investigation Type	B	B|04	Functional Testing
Investigation Findings	C	C|0101	Crack in Tubing
Investigation Conclusion	D	D|0102	Material Fatigue
Clinical Signs	E	E|0501	Swelling
Health Impact	F	F|0901	Minor Injury
Component	G	G|030201	Tubing Assembly

The Adverse Event Reporting terminology is composed of four sets of terminologies: (1) Medical device problem terminology, (2) components terminology, (3) cause investigation terminology and (4) Health Effects terminology. Note that for an effective monitoring of adverse events, means of effectively identifying devices as well as the category they belong to (e.g. GMDN) are important. 

⚖️ Harmonization with Global Standards

• ISO/TS 19218-1 & -2 (Hierarchical Coding Structures)
• FDA MDR Adverse Event Codes
• GHTF/SG2 & SG5 Guidance
• MedDRA and NCI Thesaurus

This ensures interoperability and consistency across global regulatory databases.

🧭 Best Practices for Users

• Always choose the most specific code available.
• Use multiple annexes to fully describe the event.
• Refer to your jurisdiction’s reporting rules.
• For unknown causes, code at a higher level (e.g., “mechanical problem”).
• Keep a record of code versions for traceability.

🤝 IMDRF Adverse Event Terminology Collaboration

The development and management of the IMDRF Adverse Event Terminology involve contributions from international regulators and partners working toward a unified global safety reporting standard.

🏗️ Developed By

Germany

United States

🧭 Managed By

IMDRF Secretariat

🌍 Practiced In

Europe

USA

Australia