Glossary Updates12 new terms added to the glossaries · October 2, 2026, 22:44 CEST
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Glossary · EU medical devices: MDR

Device classification (MDR)

Also known as: MDR classification, Risk class (MDR), Class I, IIa, IIb, III

Under the EU Medical Device Regulation (EU) 2017/745, device classification assigns each medical device to class I, IIa, IIb or III according to its intended purpose and inherent risks, using the 22 classification rules in Annex VIII. Class I includes the subgroups Is (sterile), Im (measuring function) and Ir (reusable surgical instruments).

  • EU
  • MDR

In one sentence

MDR classification puts medical devices into class I, IIa, IIb or III using the 22 rules of Annex VIII, based on intended purpose and risk.

Example

A manufacturer of a wound dressing for deep wounds that reach the dermis applies the non-invasive rules in Annex VIII, documents why the dressing is class IIb rather than IIa, and chooses the conformity assessment route for that class.

How it applies

  • Rule structure: Annex VIII has implementing rules (duration of use, invasiveness, active devices) and 22 rules grouped into non-invasive, invasive, active and special rules. Rule 11 covers software.
  • Highest class wins: If several rules apply, the rule leading to the higher class applies. Accessories are classified in their own right.
  • Consequence: The class determines the conformity assessment route, whether a notified body is involved and the post-market reporting, such as the PMS report for class I or the PSUR for class IIa and above.
  • Up-classification: Some products moved to higher classes under the MDR compared with the directive, for example many software products under Rule 11; this affected their transition periods.
  • Technical documentation: The classification rationale, naming the rule and the facts of the intended purpose it relies on, belongs in the device description of the technical documentation. A change of intended purpose requires reassessing the class.

MDR classes vs. IVDR classes

MDR classes run from I to III; IVDR classes run from A to D under seven rules. The two systems are not interchangeable: an IVD is never classified under MDR rules, and letters and numerals don’t map one to one.

Compared with the USA

The FDA also uses classes I, II and III, but its classification follows device-type regulations and the premarket pathway (510(k), De Novo, PMA), so an EU class doesn’t predict the US class; see FDA premarket pathways.