6 Major Differences Between EU’s MDR/IVDR and MDD/IVDD

The European Union has established the Medical Device Regulation (MDR) and In Vitro Diagnostic Regulation (IVDR) as replacements to the Medical Devices Directive (MDD) and ln Vitro Diagnostic Devices Directive (IVDD), which had previously been in place for almost 25 years. These new regulations aim to ensure the effectiveness and safety of medical devices marketing within the European Union.

The European Union’s Medical Device Regulation (MDR, Regulation (EU) 2017/745) and In Vitro Diagnostic Regulation (IVDR, Regulation (EU) 2017/746) replaced the former Medical Devices Directive (MDD) and In Vitro Diagnostic Devices Directive (IVDD), which had governed the sector for nearly 25 years. MDR became fully applicable on May 26, 2021, and IVDR on May 26, 2022 marking the formal end of the transition from directives to regulations.

In 2026, the regulatory landscape continues to evolve, with extended transition deadlines, the mandatory rollout of EUDAMED, and the European Commission’s December 2025 proposal to simplify the framework currently progressing through the legislative process. For medical device manufacturers operating in or entering the EU market, understanding what changed, and what is changing now, is essential to maintaining market access.

What are the six biggest differences between EU MDR/IVDR and the old MDD/IVDD? In summary: (1) EUDAMED is now a mandatory, module-by-module live database from May 28, 2026; (2) economic operators across the supply chain have clearly defined legal obligations for the first time; (3) device scope and classification has been fundamentally expanded; (4) notified body requirements are significantly stricter; (5) UDI is an active, phased enforcement requirement; and (6) clinical evaluation standards are substantially higher. Each is explained in detail below.

Here are the 6 most significant changes that have been introduced by the MDR and IVDR regulations. Full scope of the new regulations and detailed information can be found in the official document.

1) Changes to Eudamed

EUDAMED has evolved dramatically since 2018. The original MDR/IVDR framework envisaged the database becoming mandatory only once all six modules were fully operational. However, prolonged development delays prompted Regulation (EU) 2024/1860 to introduce a module-by-module rollout approach, allowing individual modules to become mandatory once independently declared functional.

On November 27, 2025, the European Commission published Commission Decision (EU) 2025/2371, formally confirming that four EUDAMED modules are fully functional; triggering a six-month transition period. As a result, four modules become mandatory to use from May 28, 2026: Actor Registration, UDI/Device Registration, Notified Bodies and Certificates, and Market Surveillance.

From May 28, 2026, new MDR and IVDR devices must be registered in the UDI/Device module before their first unit is placed on the EU market. Devices placed on the market before that date but continuing to be sold must be registered by November 27, 2026. All economic operators (manufacturers, authorized representatives, and importers) must hold a valid Single Registration Number (SRN) through the Actor module before placing any device on the EU market.

Importantly, EUDAMED now has both a restricted area and a public website, making device and certificate information more accessible to the public than ever before; a significant shift from its pre-MDR form.

The two remaining EUDAMED modules, Clinical Investigations and the Vigilance module, are not yet declared functional and therefore not yet subject to mandatory use. Until the Vigilance module becomes mandatory, manufacturers must continue reporting serious incidents and Field Safety Corrective Actions directly to national Competent Authorities. The Commission will issue a separate notice when these modules become mandatory, triggering another six-month transition window.

2) Role of Economic Operators

MDR Articles 10, 11, 13, 14, and 30 established clearer obligations across the supply chain for manufacturers, authorized representatives, importers, and distributors; a major improvement over the less prescriptive MDD framework. These obligations include responsibilities for technical documentation, labelling, complaint handling, post-market surveillance (PMS), and EUDAMED registration.

A key addition from Regulation (EU) 2024/1860, effective January 10, 2025: manufacturers must notify the relevant Competent Authority and, where relevant, health institutions, of any foreseeable interruption or discontinuation of supply of certain devices that could cause serious harm to patients. This obligation applies from January 10, 2025 as defined in Article 3 of Regulation 2024/1860. The notification timeline is not a blanket “six months”, the requirement is to notify “as soon as the manufacturer is aware” of a foreseeable interruption, and the notification must be made “in due time,” which will depend on the circumstances. Manufacturers should review the European Commission’s Q&A document on Article 10a for specific guidance on timing, scope of affected devices, and who must be informed.

For distributors and importers specifically, the MDCG 2021-27 Rev. 1 (December 2023) updated the Q&A on Articles 13 and 14, clarifying obligations for fulfilment service providers, traceability, UDI storage for Class III implantables, and physical verification requirements; all now active compliance requirements.

What are the new supply chain obligations under EU MDR in 2026? Under Article 10a of Regulation (EU) 2024/1860, active since January 2025, manufacturers must proactively notify competent authorities and health institutions of any foreseeable supply interruption or discontinuation for devices whose absence could cause serious harm. This is a new, active compliance obligation with no equivalent under the MDD.

3) Scope and Classification of Products

The MDR introduced an entirely revised classification framework, expanding from 4 risk classes under the MDD to a more detailed system with updated rules for software, nanomaterials, reusable surgical instruments, and substance-based devices. Many devices previously classified as Class IIa under the MDD were reclassified to Class IIb or III under the MDR; requiring notified body involvement where none was previously needed. The December 2025 EU simplification proposal introduces further classification changes, including amendments to Rule 11 of Annex VIII (the “software rule”) that would allow more medical software, including most patient self-management apps, to be classified as Class I, removing the requirement for notified body assessment.

The Commission expects adoption of the simplification proposal by the co-legislators by Q2 2027, and provisions may be subject to change during the legislative procedure. Between now and adoption, the text will be debated, amended, and renegotiated. Manufacturers should treat the proposed Rule 11 changes as a direction of travel, not a confirmed outcome. Current MDR classification rules remain fully in force.

In April 2026, the MDCG also published a revised version of its classification guidance (MDCG 2021-24), introducing terminological clarifications and additional explanatory notes under Rule 8 for long-term and implantable devices.

How did MDR change medical device classification compared to MDD? The MDR introduced a substantially more detailed classification system. Many devices previously classified as Class IIa under the MDD were reclassified to Class IIb or Class III under the MDR, requiring notified body involvement for the first time. Software classification under Rule 11 also changed significantly, with most clinical decision-support software moving from Class I to Class IIa or higher.

For IVDs, the IVDR reclassified approximately 80–90% of devices previously self-certified under the IVDD into classes now requiring notified body involvement; a fundamental shift that continues to create compliance pressure.

4) Changes to Notified Bodies

Why is notified body capacity still a problem under EU MDR in 2026? Despite growth in designated bodies, now 50 under MDR and 17 under IVDR, demand continues to outpace supply. Average review timelines of 13–18 months for complex devices, combined with approaching legacy device transition deadlines in 2027 and 2028, mean the backlog pressure is expected to worsen before it improves. Engaging a notified body early is a strategic necessity.

The MDR/IVDR’s stricter designation requirements for notified bodies did result in a significant reduction in the number of designated bodies; particularly for IVDR, where capacity remains a critical challenge. As of May 2025, there are 50 notified bodies designated under the MDR and 17 designated under the IVDR. While this represents meaningful growth from prior years, capacity remains severely constrained relative to demand. Despite the increasing numbers of designated bodies, overall submission quality from manufacturers is still reported as poor, with 75% of notified bodies reporting submissions that require significant remediation before review can proceed adding to effective timeline delays that already average 13 to 18 months for complex devices.

In December 2025, the European Commission published a draft implementing regulation to harmonize notified body practices under MDR/IVDR, targeting divergent interpretations of Annex VII requirements: including quotation information, conformity assessment timelines, and re-certification processes. If adopted, standardized maximum timelines would apply to conformity assessments: 30 days for application review, 120 days for QMS audits, and 90 days for product verification; changes that would materially improve predictability for manufacturers.

Notified bodies are currently unhappy with the proposed standardized timelines and are pushing to change them during the consultation process. The final implementing regulation, if adopted as planned in Q1 2026 with gradual application through January 2028, may look different from the draft. Manufacturers should not plan against these timelines as confirmed until the regulation is formally adopted.

Notified body capacity constraints remain one of the most urgent challenges in the EU regulatory landscape. Manufacturers are strongly advised to engage with notified bodies early rather than waiting for the end of transition periods.

5) Addition of Unique Device Identification (UDI) System

What is the UDI system under EU MDR and when does it apply? The Unique Device Identification (UDI) system requires a machine-readable code on device labels and packaging that links each device to a registration record in EUDAMED. Compliance is phased by device class and is now fully in force for most device categories. From May 28, 2026, all new devices must be registered in EUDAMED’s UDI/Device module using their UDI before being placed on the EU market.

The UDI system is no longer a future requirement; it is an active, enforceable obligation with staggered deadlines that are now in their final phases. Under the MDR, UDI requirements have been applied to Class III devices since May 2021, Class IIa and IIb since May 2023, and Class I since May 2025. Class I reusable devices have until May 2027 to implement UDI on the device itself. For IVDs, a UDI will be required for Class I medical devices, Class B, and Class C IVDs from May 26, 2026, meaning IVDR manufacturers of these device classes who have not yet implemented UDI labelling are now in a compliance gap that requires immediate attention.

The connection between UDI and EUDAMED is now central to compliance: all devices must be registered using their UDI in EUDAMED’s UDI/Device module before being placed on the EU market from May 28, 2026. The Basic UDI-DI (BUDI-DI) is the primary key grouping devices in EUDAMED, and existing product families must be uploaded by November 27, 2026 to maintain current UDI-DI structures.

Additionally, importers and distributors now have active UDI traceability obligations under MDCG 2021-27 Rev. 1: including storing UDIs for Class III implantable devices and devices determined by specific EUDAMED measures.

6) Changes to Clinical Evaluation Processes

How has clinical evaluation changed under EU MDR compared to MDD? Under the MDD, literature reviews and informal equivalence claims were widely accepted as clinical evidence. Under MDR Article 61 and Annex XIV, the bar is substantially higher: equivalence claims require a documented contractual arrangement with the equivalent device’s manufacturer (with rare exceptions), literature reviews must be systematic and comprehensive, and the Clinical Evaluation Report must be a living document updated throughout the device lifecycle. Notified bodies are actively scrutinizing these submissions, and deficiencies in clinical data remain one of the most common causes of certification delays.

The MDR’s clinical evaluation framework under Article 61 and Annex XIV represents one of the most substantial departures from the MDD. Evidence that was previously acceptable, such as literature reviews or informal equivalence claims, now faces significantly higher scrutiny from notified bodies.

Key MDCG guidance now active includes MDCG 2020-5 (equivalence assessment), MDCG 2020-6 (legacy device clinical evidence), and MDCG 2023-7 (December 2023: guidance on clinical investigation exemptions under Article 61(4)–(6) and “sufficient access” standards for equivalence claims). The Clinical Evaluation Report (CER) is now the cornerstone of technical documentation, requiring regular lifecycle-based updates.

The December 2025 EU simplification proposal introduces meaningful changes to the clinical evidence framework: the conditions for relying on data from an equivalent device are proposed to be made more flexible, and a new definition of “well-established technology device” would allow more proportionate evidence requirements for eligible devices.

The proposal also expands the definition of clinical data to include any studies published in scientific literature and other clinical experience published in peer-reviewed sources; a meaningful broadening that could reduce the clinical investigation burden for many manufacturers once adopted.

The simplification proposal would also extend the validity of CE certificates from the current five-year limit to indefinite validity with periodic risk-based reviews by the notified body, a change that, while not directly a clinical evaluation requirement, would significantly reduce the frequency with which Clinical Evaluation Reports and Post-Market Clinical Follow-up plans need to drive full recertification cycles. This is a material benefit for manufacturers of well-established technologies if adopted.

Note: these proposals have not yet been adopted. The Commission anticipates co-legislator adoption no earlier than Q2 2027. Current MDR clinical evidence requirements remain fully in force.

Conclusion

Key actions for manufacturers right now in May 2026:

• Register in EUDAMED’s Actor module and obtain your SRN before placing any new device on the EU market from May 28, 2026
• Register all devices continuing to be sold after May 28, 2026 in the UDI/Device module by November 27, 2026
• Engage your notified body immediately if you have legacy devices requiring MDR transition by the 2027 or 2028 deadlines
• Review your Article 10a obligations and put a supply interruption notification process in place
• Monitor the simplification proposal’s progress but plan your compliance programs against current MDR/IVDR rules

The shift from MDD/IVDD to MDR/IVDR was not just a regulatory update, it was a fundamental restructuring of how medical devices are evaluated, tracked, and monitored throughout their lifecycle in the EU. With EUDAMED mandatory use arriving in May 2026, notified body capacity still under strain, and the European Commission’s December 2025 simplification proposal working through the legislative process, the regulatory environment is still actively evolving. Manufacturers who stay ahead of these changes (rather than reacting to them) are best positioned to protect their EU market access and support patients safely.

Q&A:

1. What are the six biggest differences between the EU MDR/IVDR and the old MDD/IVDD? The six most significant changes are: (1) EUDAMED is now a mandatory, module-by-module live database from May 28, 2026; (2) economic operators across the supply chain have clearly defined legal obligations for the first time; (3) device scope and classification has been fundamentally expanded; (4) notified body requirements are significantly stricter; (5) UDI is an active, phased enforcement requirement; and (6) clinical evaluation standards are substantially higher. Each of these represents a meaningful departure from the MDD/IVDD framework that governed the sector for nearly 25 years.
2. What is EUDAMED and what changed about it in May 2026? EUDAMED is the EU’s central database for medical devices. Following prolonged development delays, Regulation (EU) 2024/1860 introduced a module-by-module rollout approach rather than waiting for all six modules to be fully operational. On May 28, 2026, four modules became mandatory: Actor Registration, UDI/Device Registration, Notified Bodies and Certificates, and Market Surveillance. From that date, all new MDR and IVDR devices must be registered in the UDI/Device module before their first unit is placed on the EU market, and all economic operators must hold a valid Single Registration Number (SRN) through the Actor module. The two remaining modules, Clinical Investigations and Vigilance, are not yet mandatory, and until the Vigilance module becomes active, manufacturers must continue reporting serious incidents directly to national Competent Authorities.
3. What new supply chain obligations do manufacturers, importers, and distributors face under the MDR? The MDR established clearer obligations across the supply chain than the MDD ever did, covering technical documentation, labelling, complaint handling, post-market surveillance, and EUDAMED registration. A significant addition from Regulation (EU) 2024/1860, active since January 10, 2025, requires manufacturers to notify the relevant Competent Authority, and where relevant, health institutions, of any foreseeable interruption or discontinuation of supply for devices whose absence could cause serious harm to patients. The notification must be made as soon as the manufacturer is aware of the foreseeable interruption, with timing dependent on circumstances. For importers and distributors, MDCG 2021-27 Rev. 1 clarified active obligations around UDI traceability, physical verification, and fulfillment service provider responsibilities.
4. How did device classification change under the MDR compared to the MDD? The MDR introduced a substantially more detailed classification system. Many devices previously classified as Class IIa under the MDD were reclassified to Class IIb or Class III, requiring notified body involvement for the first time. Software classification also changed significantly under Rule 11, with most clinical decision-support software moving from Class I to Class IIa or higher. For IVDs, the shift was even more dramatic, approximately 80–90% of devices previously self-certified under the IVDD were reclassified into categories now requiring notified body involvement. In April 2026, the MDCG also published a revised classification guidance document (MDCG 2021-24) with additional clarifications under Rule 8 for long-term and implantable devices.
5. Are there proposed changes to device classification that manufacturers should be aware of?Yes. The European Commission’s December 2025 simplification proposal includes amendments to Rule 11 of Annex VIII (the software rule) that would allow more medical software, including most patient self-management apps, to be classified as Class I, removing the requirement for notified body assessment. However, these proposals have not yet been adopted, and current MDR classification rules remain fully in force. Co-legislator adoption is not anticipated before Q2 2027, and the text may change during the legislative process. Manufacturers should treat the proposed changes as a direction of travel rather than a confirmed outcome.
6. Why is notified body capacity still a problem in 2026, and what can manufacturers do about it? Despite growth in designated bodies, now 50 under MDR and 17 under IVDR, demand continues to significantly outpace supply. Average review timelines of 13–18 months for complex devices are compounded by poor submission quality, with 75% of notified bodies reporting that submissions require significant remediation before review can even begin. With legacy device transition deadlines approaching in 2027 and 2028, the backlog pressure is expected to worsen before it improves. Manufacturers are strongly advised to engage with their notified body as early as possible rather than waiting for transition deadlines, and to invest in submission quality to avoid avoidable delays.
7. What is the UDI system and where does compliance stand in 2026? The Unique Device Identification (UDI) system requires a machine-readable code on device labels and packaging that links each device to a registration record in EUDAMED. Compliance is phased by device class and is now in its final stages. Under the MDR, UDI requirements are already in force for Class III, IIa, IIb, and Class I devices, with Class I reusable devices having until May 2027. For IVDs, Class B and Class C devices and Class I IVDs must have UDI in place from May 26, 2026, manufacturers in these categories who have not yet implemented UDI labelling are in an active compliance gap. From May 28, 2026, all new devices must also be registered in EUDAMED’s UDI/Device module using their UDI before being placed on the EU market.
8. How has the clinical evaluation process changed under the MDR compared to the MDD? The change is substantial. Under the MDD, literature reviews and informal equivalence claims were widely accepted as clinical evidence. Under MDR Article 61 and Annex XIV, the bar is significantly higher: equivalence claims require a documented contractual arrangement with the equivalent device’s manufacturer, literature reviews must be systematic and comprehensive, and the Clinical Evaluation Report must be a living document updated throughout the device lifecycle. Notified bodies are actively scrutinizing these submissions, and deficiencies in clinical data remain one of the most common causes of certification delays. Key MDCG guidance now in effect includes MDCG 2020-5 on equivalence assessment, MDCG 2020-6 on legacy device clinical evidence, and MDCG 2023-7 on clinical investigation exemptions.
9. What does the December 2025 EU simplification proposal mean for clinical evaluation requirements? The proposal introduces several meaningful changes to the clinical evidence framework. The conditions for relying on data from an equivalent device are proposed to be more flexible, and the definition of clinical data would be expanded to include studies published in scientific literature and peer-reviewed clinical experience, a broadening that could reduce the clinical investigation burden for many manufacturers. A new definition of “well-established technology device” would allow more proportionate evidence requirements for eligible devices. The proposal also introduces indefinite CE certificate validity with periodic risk-based reviews, replacing the current five-year limit, a significant benefit for manufacturers of established technologies. However, none of these changes have been adopted yet, and current MDR requirements remain fully in force until at least Q2 2027.
10. What are the most urgent actions manufacturers should be taking right now in May 2026? There are five priorities. First, register in EUDAMED’s Actor module and obtain your SRN before placing any new device on the EU market from May 28, 2026. Second, register all devices continuing to be sold after that date in the UDI/Device module by November 27, 2026. Third, engage your notified body immediately if you have legacy devices requiring MDR transition by the 2027 or 2028 deadlines, given current backlogs, there is no time to wait. Fourth, review your Article 10a obligations under Regulation (EU) 2024/1860 and put a supply interruption notification process in place. Fifth, monitor the progress of the December 2025 simplification proposal, but plan your compliance programs against current MDR/IVDR rules until the proposal is formally adopted.