MDCG 2024-14 Rev.1 – Updated guidance on Master UDI-DI for contact lenses

In August 2025, the Medical Device Coordination Group (MDCG) released a revised version of guidance 2024-14, focusing on the application of Master UDI-DI for contact lenses. This update clarifies how manufacturers should manage UDI assignment for devices with numerous variants.

When to apply Master UDI-DI

For device families with multiple technical variants sharing the same intended purpose.
Where differences do not alter the core performance or risk profile.
When the same Basic UDI-DI and essential product information apply.

Standard vs. custom-made lenses

Standard lenses: grouped under a Master UDI-DI, easing identification and reporting.
Custom-made lenses: documented separately, with distinct requirements; not all parameter adjustments qualify a lens as custom-made.

Data and registration requirements

Manufacturers must ensure consistency across Basic UDI-DI, Master UDI-DI, and UDI-DI entries. Updates in EUDAMED must reflect changes affecting traceability, with complete audit trails for modifications.

Frequent compliance pitfalls

assigning too many UDIs instead of grouping variants.
material modifications treated as “variants” instead of requiring a new Master UDI-DI.
discrepancies between IFU, labelling, and EUDAMED entries.

Summary

The Master UDI-DI system simplifies surveillance, reduces regulatory burden, and increases transparency. For patients, it means better assurance of device traceability and safety — a key step in reinforcing trust in one of the most widely used medical devices worldwide.