Background of EU MDR classification
New and legacy devices seeking regulatory compliance in the European Union (EU) need to confirm their classification under the Medical Devices Regulation 2017/745 (MDR) to determine the conformity assessment requirements. The MDR introduced four new classification rules that shifted conformity assessment requirements for devices already classified under the MDD. It also brought some products that were not previously regulated as medical devices under its scope, such as some products that do not have an explicit medical purpose but fit the risk profile of a medical device (e.g., some cosmetic and aesthetic devices listed in Annex XVI) and some software.
How medical devices are classified under the MDR
Classification is based on the intended purpose of the device, which articulates how the device functions, how the device should be used, and its clinical use scenario. You will classify your device according to the 22 rules laid out in Annex VIII of the MDR. The rules follow a risk-based logic based on the characteristics of the device, including its duration of contact with the body, degree of invasiveness, and whether it is active or non-active (i.e., does it require an energy source). The rule that most applies to your device will decide its risk classification. If more than one rule is relevant to your device, the rule with the highest risk will apply. MDCG 2021-24 Guidance on classification of medical devices provides interpretations of the rules and how to apply them in practice.
Devices are classified into four tiers of increasing risk, though the lowest-risk tier has three sub-classifications:
- Class I - low risk (e.g., wheelchairs)
- Class Is – sterile condition (e.g., surgical drapes)
- Class Im – measuring function (e.g., non-sterile thermometers)
- Class Ir – reusable surgical (e.g., certain surgical scalpels)
- Class IIa - moderate risk (e.g., ultrasound devices)
- Class IIb - high-moderate risk (e.g., ventilators, blood bags)
- Class III - high risk (e.g., pacemakers, heart valves)
How classification affects regulatory requirements under the MDR
Classification dictates your conformity assessment route and the level of involvement by a Notified Body (NB), even if you have a legacy device. For high-risk devices, your NB can mandate resource-intensive conformity assessment requirements that can extend your timeline to market, such as pre-market clinical investigations or the need for expert panel review of your clinical data. Classification will also influence activities you must sustain throughout the life cycle of the device to remain on the EU market, such as your post-market surveillance and vigilance reporting requirements (including the types of reports, depth of information provided, and frequency) and supply chain or labeling traceability requirements. For legacy devices transitioning to the MDR, your final transition deadline is determined by your device’s classification under the MDR, not by the MDD.
