MDR device classes — Class I · IIa · IIb · III

Regulatory basis

MDR 2017/745, Article 51 and Annex VIII. MDR uses a four-class system with Class I subdivided into sub-classes based on sterility, measuring function, and reusable surgical instrument status.

Disclaimer

This site provides general information only and does not constitute legal or regulatory advice. Always consult the official regulation text and a qualified regulatory professional.

Class overview

Class	Risk level	Notified body required?	Examples
Class I	Lowest	No (self-declaration)	Bandages, walking frames, non-sterile gloves, stethoscopes
Class Is	Lowest — sterile	Yes (sterility aspect only)	Sterile wound dressings, sterile drapes
Class Im	Lowest — measuring function	Yes (measuring aspect only)	Graduated syringes, clinical thermometers
Class Ir	Lowest — reusable surgical instrument	Yes (reprocessing aspects)	Reusable scalpels, forceps, retractors
Class IIa	Low-to-medium	Yes	Hearing aids, dental materials, short-term surgically invasive devices
Class IIb	Medium-to-high	Yes	Ventilators, infusion pumps, orthopaedic implants (non-Class III)
Class III	Highest	Yes (with enhanced scrutiny for some)	Coronary stents, heart valves, total hip implants, neurostimulators

Class I and its sub-classes

Class I — Standard

Class I devices are the lowest-risk category. Manufacturers can self-certify compliance without notified body involvement. They must:

Prepare technical documentation (Annex II and III)
Implement a quality management system (or, for non-system/procedure-pack manufacturers, a simplified system)
Register in EUDAMED
Sign an EU Declaration of Conformity
Affix the CE mark

Class Is — Supplied in sterile condition

Class Is devices are Class I devices placed on the market in a sterile state. The manufacturer must involve a notified body, but only for the aspects relating to the establishment, securing and maintenance of sterile conditions (Annex IX, Section 1 or Annex XI, Part A).

The notified body does not assess the rest of the device's conformity — the manufacturer self-declares for those elements.

Class Im — With a measuring function

Class Im devices incorporate a measuring function for which accuracy is critical. The notified body assesses only the metrological aspects of conformity (Annex IX, Section 1 or Annex XI, Part A).

Examples: clinical thermometers, BP cuffs with a calibrated scale, sphygmomanometers.

Note: a measuring function only engages Class Im if accuracy is clinically critical. A rough scale or indicator does not typically trigger Class Im.

Class Ir — Reusable surgical instruments

Class Ir applies to reusable surgical instruments intended to be used in surgical procedures and which can be reprocessed for reuse. The notified body assesses aspects relating to reprocessing validation and instructions (Annex IX Section 1 or Annex XI Part A).

Class IIa

Class IIa represents low-to-medium risk. Full notified body involvement is required. The conformity assessment route is the manufacturer's choice from:

Annex IX (QMS + technical documentation review)
Annex X (EU type examination) + Annex XI Part A or B (production quality assurance or product verification)

For Class IIa, the notified body assesses at least one representative device per generic device group as part of its technical documentation review under Annex IX.

Typical Class IIa devices

Short-term surgically invasive devices not placed in the heart/CNS/central circulatory system
Long-term surface-contacting devices
Hearing aids
Most dental devices (fillings, crowns)
Ultrasound imaging equipment
Anaesthesia masks
Blood transfusion tubing

Class IIb

Class IIb represents medium-to-high risk — devices that may pose significant risk if they fail. Full notified body involvement with more extensive assessment is required.

For Class IIb devices, the notified body must assess the technical documentation of at least one representative device per category and may request additional sampling.

Typical Class IIb devices

Ventilators and anaesthetic machines
Infusion pumps
Intensive care monitors
Orthopaedic implants (non-total joint replacement, depending on classification rules)
External bone fixation systems
Dialysis machines
Surgical lasers

Class IIb → Class III scrutiny (Art. 54)

For certain high-risk Class IIb devices (specifically those in contact with the heart, central circulatory system, or CNS intended for long-term use, and implantable Class IIb devices), the notified body is required to consult an expert panel or NCA before issuing or renewing a certificate. This is the Article 54 scrutiny procedure.

Class III

Class III is the highest risk class. It includes:

All active devices intended to administer medicines, energy, or other substances into or from the body, where the administration can be dangerous
Devices in contact with the central circulatory system or CNS for long-term use
Devices with biological components (human or animal origin) with systemic absorption
Total joint replacements
Coronary and peripheral vascular stents
Heart valves (non-biological, and biological)
Spinal implants
Neurostimulators
Active implantable devices (formerly governed by AIMDD)

Class III conformity assessment

Class III always requires Annex IX (QMS and technical documentation assessment). The notified body must:

Assess the full technical documentation (not just a representative device)
Issue a clinical evaluation consultation under Annex IX, Section 5.1 for devices without a predicate with an established clinical record

For implantable Class III devices and Class IIb devices covered by Art. 54, the notified body must submit its clinical evaluation assessment to an expert panel for a scientific opinion before issuing a certificate.

PSUR requirement

Manufacturers of Class III and implantable Class IIb devices must prepare a Periodic Safety Update Report (PSUR) annually, updated as needed. PSURs are submitted to the notified body and uploaded to EUDAMED.

Selecting the right conformity assessment route by class

Class	Available routes
I (standard)	Self-declaration (Annex IV)
Is / Im / Ir	Partial NB involvement (Annex IX §1 or Annex XI Part A) + self-declaration for remainder
IIa	Annex IX, or Annex X + Annex XI (Part A or B)
IIb	Annex IX, or Annex X + Annex XI (Part A or B)
III	Annex IX only

Official references

Reference	Description
MDR Art. 51	Classification of medical devices
MDR Annex VIII	Classification rules
MDR Annex IX	Conformity assessment based on QMS
MDR Art. 54	Special procedure for Class IIb and III
MDR Art. 61	Clinical evaluation
MDCG 2021-24	Software classification

Class overview​

Class I and its sub-classes​

Class I — Standard​

Class Is — Supplied in sterile condition​

Class Im — With a measuring function​

Class Ir — Reusable surgical instruments​

Class IIa​

Typical Class IIa devices​

Class IIb​

Typical Class IIb devices​

Class IIb → Class III scrutiny (Art. 54)​

Class III​

Class III conformity assessment​

PSUR requirement​

Selecting the right conformity assessment route by class​

Related pages​

Official references​