Medical Devices Classification UK

Medical Devices Classification UK

In the UK, a Medical device is defined as any medical instrument, apparatus, appliance, software, implant, reagent, material or other article intended by the manufacturer to be used, alone or in combination, for human beings.

A full definition can be found in the medical device regulations 2002 (as amended).

UK Medical Device Requirements Image
  • In the United Kingdom (UK), devices are classified into four classes: class I, Class IIa, Class IIb and Class III.
  • Medical device classification is in accordance with the UK Medical Device Regulations 2002 and the class is attributed by considering the purpose of the device and how long the device is intended to be used.
  • Classification is also based on the medical device risk level to the end user, as set out in Annex IX of the MDD 93/42/EEC (UK MDR 2002).
  • Manufacturers may need to demonstrate that their medical device meets the regulatory requirements by carrying out a conformity assessment.
  • The assessment route depends on the classification of the device.
  • The risk class determines whether a conformity assessment would be required (which would be carried out by a Notified Body).


Difference between Medical Devices Classification UK

Class I Medical Devices

A class I medical device is the lowest risk classification, for example, a plaster or bandage used to cover a small cut. Devices such as these would not require attention from an approved body.

Examples of Class I Medical Devices

• Bandages / plasters
• Stethoscopes
• Wheelchairs
• Examination lights
• Medicine spoons

Class IIa Medical Devices

Class IIa devices are devices that are known to present a  medium risk upon use, for example a hearing aid for someone who is suffering from hearing loss.Naturally, anything that falls into the category of Class IIa is considered to present more of a risk to the user than a Class I Medical Devices.

Examples of Class IIa Medical Devices

• Hearing aids
• Surgical clamps
• Dental fillings
• Contact lenses
• TENS devices

Class IIb Medical Devices

Devices classified as Class IIb are more complex medium risk devices.  A scenario of a class IIb device being used would be somebody receiving a diagnostic X-ray after a suspected fracture or break to a bone.

Examples of class IIb Medical Devices

• Diagnostic X-ray
• Ventilators
• Bone-fixation plates
• Condoms
• Surgical lasers

Class III Medical Devices

Devices classified at Class III are have the highest risk and complexity associated with them. A Class III device could be something that directly supports or sustains the life of the user such as a  pacemaker or an implant such as a prothesis. Obviously, if medical devices such as these were to be of insufficient quality, they could cause serious or even life threatening complications, hence them being issued the highest classification available and undergoing the greatest scrutiny in order to achieve accreditation.

Examples of class III Medical Devices

• Pacemaker
• Heart Valves
• Breast Implants
• Joint Replacement System
• Contraceptive IUD’s

All devices placed on the market in Great Britain  must be registered with the MHRA, regardless of their assigned classification.


We hope this blog was useful in helping you understand the difference between a Class I, IIa, IIb and III medical devices .

Do you want to learn more about device classifications in the EU? Why not check out our other two blogs below. Additionally, you can check out Patient Guard’s Quality Services here and Regulatory Services here, that will assist you in getting your medical devices to market in the UK and EU.
EU Classifications blog
About the Author
Connor Campbell
Connor Campbell

Connor is a recent graduate in ‘Digital Media and Web Technologies”, where he graduated with a First Class Honours degree at Blackpool & The Fylde College. Connor joined Patient Guard in September 2021 as the digital marketing assistant.

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