Cheat Sheet: MDCG Guidance on Medical Device Classification

Assigning the proper class to a medical device (MD) is one of the most important activities carried out by a manufacturer. The Medical Device Coordination Group (MDCG) (1) released guideline MDCG 2021-244 (2) in October, providing clarification on how medical devices (MDs) should be classified under the Medical Device Regulation (MDR) 2017/745. 

Published on:
April 8, 2022
Written by:
Hasma Boudaoui, Mercè Guerra, Ainoa Forteza

The MD manufacturer is responsible for assigning the proper classification to its MD, as it depends on the product’s claims and functionalities. Incorrectly classifying a MD could significantly impact product development, considering different regulatory, nonclinical, and clinical requirements depend on the classification.  

The MDCG issued this guidance to clarify the classification system under MDR and allow for easier comprehension of the MD classifications. The guidance includes a stepwise flowchart (3) illustrating how each rule should be applied and providing practical examples. 

MDCG Guidance – Medical Device Classes

In the EU, MDs are sorted into four different classes, from low to high risk:  

  • Class I 
  • Class IIa 
  • Class IIb 
  • Class III 

Classification is based on a risk level system that considers the degree of invasiveness, the part of the body affected, the contact duration with the body, and other elements. These elements, along with the intended use of the device, should help manufacturers determine which “classification rules” apply to their device.  

If more than one rule applies, the manufacturer should assign the highest risk class to the device. For example, if both Rule X (Class IIb) and Rule Y (Class III) apply to the device, the device would be assigned the higher one: Class III.  

If the regulatory classification of the device is not clear, or it could be controversial, Alira Health recommends seeking out clarification. Particularly with borderline products, e.g., products that could be seen as medicinal, cosmetics, or food supplements, clarification is important as not properly categorizing the product may have important consequences for its development. 

Regulatory Expertise

The Alira Health Regulatory team provides support to manufacturers on: 

  • Properly classifying a device under MDR through a classification assessment that evaluates the MD’s intended use, target population, and functionality 
  • Identifying which requirements are applicable to your device based on the assigned class, and providing regulatory, operational, and strategic support to commercialize the product  

Learn more about our regulatory support.


  1. The Medical Device Coordination Group (MDCG) is an expert group, set up by both Medical Devices and In Vitro Diagnostic Devices regulations, respectively 2017/745 and 2017/746, whose members are representing EU competent authorities. Their main objective is to help and guide the European Commission and countries in implementing properly both regulations.
  2. MDCG 2021-24 Guidance on classification of medical devices mdcg_2021-24_en.pdf (
  3. MDCG 2021-24 Guidance on classification of medical devices. Explanations of individual rules: Graphical summary mdcg_2021-24_en.pdf (


  • MD: Medical Devices 
  • MDCG: Medical Device Coordination Group 
  • MDR: Medical Device Regulation 


Welcome to Alira Health. This site is best viewed in Chrome, Microsoft Edge, or Firefox.