Purpose of the Measure

In accordance with Article 27 of the MDR and related delegated regulations, the introduction of the Master UDI-DI aims to simplify the identification of product families.
Instead of assigning thousands of individual UDI numbers, one common identifier is used for groups of similar products — the Master UDI-DI.

Who Is Affected by the New Requirements?

The new obligations apply to the following medical devices:

  • Contact lenses (Class IIa/IIb),

  • Spectacle frames, spectacle lenses, and ready-to-wear reading spectacles (Class I).

The implementation deadlines are as follows:

  • For contact lenses: from 9 November 2026,

  • For frames, lenses, and ready-to-wear corrective spectacles: from September 2028.

What Needs to Be Done?

The implementation of the Master UDI-DI consists of three key steps:

  1. Assigning the identifier – according to the rules set by UDI issuing entities, a common identifier must be assigned for groups of devices with similar design characteristics.

  2. Labelling the device – once assigned, the Master UDI-DI must appear on the product label and all higher levels of packaging, in accordance with Article 27(4) MDR.

  3. Registration in EUDAMED – the Master UDI-DI must be registered in the EUDAMED UDI/device registration module. This obligation is directly linked to the date the identifier is assigned.

Note: Manufacturers may voluntarily assign a Master UDI-DI before the mandatory deadlines.
The MDCG strongly recommends taking advantage of this option to avoid workload peaks and to benefit from the full functionality of the EUDAMED system early on.

Integration with Post-Market Surveillance

Once the Vigilance and PMS modules of EUDAMED become mandatory (expected in Q3 2026), any previously assigned Master UDI-DI must also be used in adverse event reporting and corrective action documentation (FSCA).
This means that identification data will become part of a broader monitoring and reporting system, integrating UDI information with safety processes.

Next Steps

The MDCG has announced the publication of additional supporting documents, including:

  • an updated version of MDCG 2024-14 for contact lenses,

  • a new guidance MDCG 2025-XX for Class I devices (spectacle frames and corrective spectacles).

Source: MDCG 2025-7 Position Paper: Timelines of implementation of ‘Master UDI-DI’ to contact lenses and spectacle frames, spectacle lenses and ready-to-wear reading spectacles