Understanding Medical Device Classification: Insights from MDCG 2021-24 Rev.1

What Is MDCG 2021-24 Rev.1?

The MDCG 2021-24 Rev.1 is a guidance document published by the Medical Device Coordination Group (MDCG). It clarifies how to apply the classification rules set out in the MDR (EU) 2017/745. The document helps stakeholders determine the correct risk class for medical devices, which affects the regulatory pathway, including conformity assessment procedures.

This guidance updates and refines earlier versions, addressing common questions and providing practical examples to improve consistency in classification decisions.

Why Accurate Classification Matters

Classifying a medical device correctly is essential because it determines:

• The level of regulatory scrutiny required

• The type of conformity assessment procedures to follow

• The involvement of notified bodies

• Post-market surveillance obligations

  
  

Incorrect classification can lead to delays in market access, increased costs, or even safety risks if a device is under-classified.

Overview of Classification Rules

The MDR divides medical devices into four classes based on risk:

• Class I (low risk)

• Class IIa (medium risk)

• Class IIb (medium-high risk)

• Class III (high risk)

  
  

The classification depends on factors such as:

• Duration of contact with the body

• Invasiveness

• Active or non-active status

• Intended purpose and function

  
  

MDCG 2021-24 Rev.1 explains how to interpret these factors and apply the 22 classification rules in Annex VIII of the MDR.

Key Updates in MDCG 2021-24 Rev.1

This revision provides clearer explanations and examples for complex cases, including:

• Devices with multiple functions

• Software as a medical device (SaMD)

• Devices incorporating medicinal substances

• Reusable surgical instruments

  
  

For example, the guidance clarifies that software controlling a medical device should be classified according to the device’s risk class, but standalone software must be classified based on its intended use and potential risk.

Applying the Classification Rules Step-by-Step

The guidance recommends a systematic approach:

1. Identify the intended purpose of the device as described by the manufacturer.

2. Determine the duration and invasiveness of contact with the body.

3. Check if the device is active or non-active.

4. Apply the relevant classification rules from Annex VIII.

5. Consider any special cases, such as devices with medicinal substances or software.

6. Document the classification decision with justification.

   
   

This process helps avoid misclassification and supports transparent regulatory submissions.

Examples of Classification Decisions

Example 1: A Non-Invasive Blood Pressure Monitor

• Intended for continuous monitoring

• Non-invasive, active device

• Rule 10 applies (active devices intended for diagnosis)

  
  

Classification: Class IIa

Example 2: Implantable Cardiac Pacemaker

• Implantable device

• Active and life-sustaining function

• Rule 8 applies (implantable devices)

  
  

Classification: Class III

Example 3: Software for Diagnostic Imaging Analysis

• Standalone software

• Intended to provide diagnostic information

• Rule 11 applies (software classification)

  
  

Classification: Class IIa or higher depending on risk

These examples illustrate how the guidance helps clarify complex cases.

Challenges and Common Questions

Manufacturers often face challenges such as:

• Devices with multiple intended purposes

• Combination products (device plus medicinal substance)

• Software updates changing risk profiles

  
  

MDCG 2021-24 Rev.1 addresses these by emphasizing the need for a thorough risk assessment and clear documentation. It also advises consulting notified bodies early when classification is uncertain.

Practical Tips for Manufacturers

• Review the intended use carefully and align it with classification rules.

• Keep detailed records of classification decisions and rationale.

• Monitor regulatory updates and guidance revisions.

• Engage with notified bodies early in the development process.

• Train your regulatory team on the latest classification guidance.

  
  

Impact on Regulatory Strategy

Correct classification influences:

• The conformity assessment route (self-certification vs. notified body involvement)

• Technical documentation requirements

• Clinical evaluation needs

• Post-market surveillance plans

  
  

Understanding MDCG 2021-24 Rev.1 helps manufacturers plan regulatory submissions efficiently and avoid costly rework.

Conclusion: Navigating the Classification Landscape

In conclusion, the MDCG 2021-24 Rev.1 guidance is essential for ensuring accurate medical device classification. By following the outlined steps and understanding the classification rules, manufacturers can navigate the complexities of regulatory compliance. This guidance not only aids in achieving market success but also enhances patient safety and operational efficiency.

For further insights, please refer to the official MDCG 2021-24 Rev.1 guidance.

By adhering to these principles, organizations can position themselves as leaders in the medical device industry, ensuring compliance with global regulations while securing top talent for their teams.