Internet Explorer 11 (IE11) is not supported. For the best experience please open using Chrome, Firefox, Safari or MS Edge

The Medical Devices Regulation (MDR) is set to replace the existing regulatory system under the MDD for medical devices in Europe. The MDR completely overhauls the regulatory framework. As a result, products that were previously certified under the existing MDD will require re-certification under the MDR.

The MDR’s original date of implementation was 26 May 2020, however, fears had arisen that the medical device industry would be negatively impacted and unprepared for a full switch to the MDR regime by then. In light of COVID-19 and the impact it has had on the medical devices directive, the decision to postpone the full date of application of the MDR to 26 May 2021 was very welcome. However, the need for transitional provisions has always been clear, primarily to prevent removal of essential products from patients who rely on them if recertification under the MDR had not been achieved in time. Transitional provisions were therefore inserted under Article 120 of the MDR. As a result, devices previously accredited under the existing MDD prior to 26 May 2021 are now permitted to be placed on the market until May 2024 and be made available to end-users until May 2025. However, one of the conditions laid down by Article 120 is that no significant changes can be made to the intended purpose or design of the relevant device post 26 May 2021.

Interpretation of a ‘significant change’

Article 120 of the MDR fails to define what constitutes a ‘significant change’. Some clarity was then dispensed from the European Commission’s guidance on ‘significant change’[1] in March of this year (the Guidance). The Guidance provides a roadmap of different assessment steps which can be taken to reach the result of determining when a change should be deemed ‘significant’ or not. Manufacturers themselves can assess their proposed change against various flowcharts in the Guidance to determine whether or not this would render the change “significant”. Changes made to the design or intended purpose of their medical device must be brought to the attention of their Notified Body, whom will assess whether the change is ‘significant’ on a case-by-case basis. For Class I medical devices requiring the involvement of a Notified Body for the first time, manufacturers of these devices must be able to justify their decision when the changes are considered non-significant.

Insignificant Changes

No administrative changes are to be considered as significant. This includes changes of the manufacturer’s name, address or legal form or changes of the authorised representative. The same applies to changes that do not have an impact on the design or intended purpose of the device. These relate to the addition of new manufacturing sites or particular changes to the quality management system. Additionally, all changes which are related to corrective actions that have been assessed and accepted by the relevant competent authority fall out of scope. Minor changes to software are also permissible and include the correction of an error which does not pose a safety risk, security updates, appearance of the user interface, operating efficiencies and changes to user interface without changes in performance.

Significant Changes

The Guidance provides a number of flow chart diagrams for either manufactures or Notified Bodies to consider when determining if a change should be deemed “significant”.

  • Chart A relate to changes to the intended purpose of the device and if the answer is yes then this is deemed a significant change. Examples include new user or patient population, change of clinical use (e.g. new anatomical site) or an extension in the intended purpose.

  • Chart B raises the question as to whether the change at issue effects the design performance specification. If the answer is yes then this is considered a significant change. This would include changing operating sources, adding new clinical data to support, changing the source of energy or alarms and adding new risks that require control measures.

  • Chart C deals with changes to software. Significant changes under this category would include new or major changes to the operating system, new user interface, new diagnostic features or new channels of inter-operability, user input replaced with closed loop algorithm, modified architecture or database structures, algorithm and major changes to the operating system.

  • Chart D considers changes in material. Significant changes within this category would include changes with regard to human/animal origin, ingredients from a new supplier with new specifications and medicinal substances impacted by the change.

  • Chart E discusses changes with regard to sterilization or packaging design that impacts sterilization. A change would be ruled significant under this category whereby the new package design impacts sterilization, an extension of expiry without prior Notified Body review of methodology, new sterilization method or a design change which impacts sterilization.

Although most of the guidance focuses on changes to the device, materials, or its intended purpose, those are not the only changes a Notified Body may rule significant enough to invalidate an MDD CE certification and thereby end the transitional period the manufacturer hoped to benefit from. Quality Management System (QMS) changes may also be considered significant. These include changes in company ownership, new facility or line modification/relocation, postmarket surveillance and vigilance issues, change in authority of the management representative and concerns about implementation or corrective actions.


The delay to the MDR has now given manufacturers a new 12 month window to renew existing or obtain new MDD certificates and provided a certificate is obtained by 26 May 2021, the transitional periods will be available to them. Availing devices can be placed on the market up to May 2024 and be made available to end-users up to May 2025. This will allow manufactures to continue to supply their medical devices whilst also preparing for the eventual re-classification under the MDR.

Understanding which changes are permissible is critical before implementing a change. Article 120 does not define what constitutes a ‘significant change’ and although the European Commission has offered guidance, it is not exhaustive. Legal advice should be obtained when manufactures are unsure as to whether their intended change would be rendered significant or not.

For more information on the scope of the MDR and its likely impact on your business, contact a member of our Product Regulatory team.

The content of this article is provided for information purposes only and does not constitute legal or other advice.

[1] MDCG 2020-3, ‘Guidance on significant changes regarding the transitional provision under Article 120 of the MDR with regard to devices covered by certificates according to MDD and AIMDD, available online at ,,accessed on 28 May 2020.

Share this: