MDCG Master UDI-DI Timelines: Contact Lenses and Spectacles 

The Medical Device Coordination Group (MDCG) has published MDCG 2025-7 Rev. 1 (December 2025), a position paper outlining timelines for implementing the “Master UDI-DI” for certain highly individualized devices, including contact lenses, spectacle frames, spectacle lenses, and ready-to-wear reading spectacles.

The document is endorsed by the MDCG and is established under Article 103 of Regulation (EU) 2017/745 (MDR) and notes it is not legally binding and does not reflect an official European Commission position.  

Scope and Background for the New Master UDI-DI Implementation

The position paper from MDCG explains that the Master UDI-DI approach is foreseen in Annex VI, Part C, Sections 6.6.1 and 6.6.2 MDR (as amended by relevant Delegated Regulations) and is intended to group highly individualized devices with similarities in relevant design parameters under a common identifier, to be assigned and registered in the EUDAMED UDI/Device registration module.  

It also references classification context: corrective contact lenses are considered class IIa (short-term) or class IIb (long-term), while spectacle frames, spectacle lenses and ready-to-wear reading spectacles are considered class I.  

Important Deadlines 

Timelines  

It is important to note that the regulatory timelines for EUDAMED implementation and Master UDI-DI requirements do not fully align. In particular, the obligation to register devices in EUDAMED becomes mandatory before the legal requirement to assign a Master UDI-DI applies to certain device categories. As a result, manufacturers must manage EUDAMED registration and vigilance reporting obligations during a transitional period in which Master UDI-DI assignment remains voluntary but may nonetheless be expected to be used once assigned. 

Plan for Phased Implementation 

Overall, manufacturers should plan for a phased implementation of the Master UDI-DI requirements, taking into account both the voluntary phase and the points at which EUDAMED modules and legal obligations become mandatory. 

• Before the mandatory application dates: Manufacturers may assign a Master UDI-DI voluntarily. If they do so, they should label it and register the device in EUDAMED promptly. 

• From the point the EUDAMED vigilance/PMS module becomes mandatory: Manufacturers should use any assigned Master UDI-DI for vigilance case reporting for the relevant device categories, regardless of whether the mandatory application dates for the Master UDI-DI Delegated Regulations have passed. 

• By the mandatory application dates: Manufacturers must be in a position to comply with the Delegated Regulations’ requirements, including Master UDI-DI assignment and the associated labelling and EUDAMED registration obligations. 

How MedEnvoy can Support Manufacturers 

MedEnvoy supports manufacturers with MDR UDI and Master UDI-DI readiness, including: 

• Defining Master UDI-DI grouping approaches for highly individualized devices 

• Preparing UDI/Device data for EUDAMED registration (mandatory use from May 2026)  

• Aligning labelling, technical documentation, and EUDAMED records 

• Planning for transition periods and integrating (Master) UDI-DI use into vigilance/PMS processes as relevant EUDAMED modules become mandatory  

If you have any questions regarding this summary or the accompanying guidance document, we encourage you to contact our team for tailored support.