The EU and the US are the two largest medical device markets in the world. Most MedTech startups with global ambitions will need to navigate both regulatory systems eventually. Understanding the fundamental differences between MDR and the FDA framework is essential for planning a multi-market regulatory strategy.
This post is not a comprehensive guide to FDA regulation — that would be a separate blog series. Instead, it is a comparative overview written from the EU perspective, highlighting the differences that matter most for EU-based startups considering US market entry.
A critical caveat upfront: Tibor's expertise is in EU MDR. He explicitly does not claim FDA expertise and recommends engaging US regulatory specialists for FDA submissions. This comparison provides the landscape; US-specific execution requires US-specific expertise.
The Fundamental Philosophical Difference
EU (MDR): The manufacturer declares conformity. A Notified Body (a private, designated organization) assesses whether the device meets the regulation. The competent authority oversees the system through market surveillance.
US (FDA): The manufacturer requests market authorization from the FDA (a government agency). The FDA reviews the submission and decides whether to authorize the device. The FDA is both the reviewer and the post-market enforcer.
This is the most important difference. In the EU, conformity assessment is delegated to Notified Bodies. In the US, the FDA itself is the gatekeeper. This affects timelines, costs, communication, and the overall regulatory experience.
Tibor's framing: "In the EU, you build your case, have it assessed by a Notified Body, and declare conformity. In the US, you submit your case to the FDA and ask for permission. The dynamic is fundamentally different — one is a conformity declaration system, the other is a pre-market authorization system."
Classification Systems
EU (MDR)
Four risk classes: I, IIa, IIb, III. Classification based on 22 rules in Annex VIII, primarily driven by the device's intended purpose, invasiveness, duration of use, and active/non-active nature.
US (FDA)
Three risk classes: I, II, III. Classification based on a system of device classification panels and product codes. Each device type is classified by the FDA based on the level of regulatory control needed to assure safety and effectiveness.
The FDA also classifies by regulatory pathway: - Class I: Generally exempt from premarket notification (510(k)) or subject to general controls only - Class II: Typically requires 510(k) premarket notification (or De Novo classification for novel devices with no predicate) - Class III: Requires Premarket Approval (PMA) — the most rigorous pathway
Key Differences
The EU and US classification systems do not align one-to-one. A device that is Class IIa in the EU may be Class II in the US, but the mapping is not consistent. Some devices classified higher under MDR (particularly software under Rule 11) may be classified lower by the FDA, and vice versa.
For startups, this means you cannot assume your EU classification translates to the US. You must classify under each system independently.
Pre-Market Pathways
EU: Conformity Assessment (via Notified Body)
The EU pathway, as covered extensively in this blog, involves: 1. Classification per Annex VIII 2. Conformity assessment per the applicable Annex (IX, X, XI) 3. Notified Body assessment of QMS and technical documentation 4. Declaration of Conformity and CE marking
The EU does not have a single "approval" moment. The process is a continuous assessment — the Notified Body reviews, issues findings, you resolve them, and eventually the NB issues a certificate. The manufacturer then declares conformity and CE marks the device.
US: 510(k), De Novo, or PMA
The FDA has three primary pre-market pathways:
510(k) Premarket Notification (most common for Class II): You demonstrate that your device is "substantially equivalent" to a legally marketed predicate device. The submission includes a comparison to the predicate, performance testing, and (sometimes) clinical data. The FDA reviews and issues a clearance decision — typically within 90 days from acceptance, though the total elapsed time can be longer.
De Novo Classification (for novel Class I/II devices with no predicate): If your device is low-to-moderate risk but no predicate device exists for a 510(k), the De Novo pathway allows you to request classification of your device as Class I or Class II. This pathway has become increasingly important for novel medical technologies, particularly software and digital health devices.
Premarket Approval (PMA) (required for Class III): The most rigorous pathway. You must provide valid scientific evidence — typically including clinical investigation data — demonstrating that the device is safe and effective. PMA submissions are extensive, and the FDA review process is thorough. PMAs can take 12-24 months for FDA review alone.
Key Differences in Pre-Market Pathways
| Aspect | EU (MDR) | US (FDA) |
|---|---|---|
| Review body | Notified Body (private) | FDA (government) |
| Outcome | NB certificate + manufacturer's DoC | FDA clearance/authorization/approval |
| Typical Class II timeline | 12-24 months total | 6-12 months (510(k)) |
| Typical Class III timeline | 24-36+ months | 12-24 months (PMA, FDA review only) |
| Predicate concept | Equivalence (for clinical evidence) | Substantial equivalence (for market authorization) |
| Interactive review | NB findings → manufacturer response | FDA interactive review, additional information requests |
Clinical Evidence Requirements
EU (MDR)
Clinical evidence is required for all devices per Article 61. The evidence must be sufficient to demonstrate safety and performance. For Class III devices, clinical investigation data is generally expected unless equivalence is strongly established. Equivalence claims are strictly assessed with three-dimensional requirements (technical, biological, clinical).
US (FDA)
Clinical evidence requirements vary by pathway: - 510(k): Clinical data is not always required. If substantial equivalence can be demonstrated through bench testing and performance data, clinical studies may not be needed. However, the FDA can request clinical data if it determines that bench data alone is insufficient. - De Novo: Clinical evidence requirements are determined on a case-by-case basis. - PMA: Clinical investigation data is typically required. Valid scientific evidence demonstrating safety and effectiveness is the standard.
Key Difference
MDR requires clinical evidence for ALL devices (though the scope and depth vary). The FDA's 510(k) pathway often does not require clinical data, instead relying on substantial equivalence to a predicate. This means that a device cleared through 510(k) may not have the same level of clinical evidence that MDR requires.
For EU startups planning US expansion, this can be an advantage — your MDR clinical evidence may exceed 510(k) requirements, making the US submission easier.
Quality System Requirements
EU (MDR)
QMS per Article 10(9), aligned with ISO 13485. The Notified Body assesses the QMS as part of the conformity assessment.
US (FDA)
Quality System Regulation (QSR) — 21 CFR Part 820, which the FDA is transitioning to the Quality Management System Regulation (QMSR) aligned with ISO 13485.
Key Difference
The FDA's transition to QMSR (aligning with ISO 13485) is reducing the gap between EU and US QMS requirements. For startups with an ISO 13485-based QMS, meeting both jurisdictions' QMS requirements is increasingly feasible with a single system.
Post-Market Requirements
EU (MDR)
Extensive post-market surveillance (PMS plan, PMS report or PSUR), post-market clinical follow-up (PMCF), vigilance reporting, and periodic clinical evaluation updates. MDR has some of the most demanding post-market requirements globally.
US (FDA)
Medical Device Reporting (MDR — confusingly, the US acronym matches the EU regulation name), which requires reporting of deaths, serious injuries, and device malfunctions. Post-market surveillance studies may be required as a condition of PMA approval. The FDA also conducts establishment inspections.
Key Difference
MDR's systematic PMS and PMCF requirements are generally more structured and demanding than the FDA's post-market framework, which is more focused on adverse event reporting than proactive surveillance. EU startups accustomed to MDR's PMS requirements will find US post-market obligations less burdensome.
Unique Device Identification
EU (MDR)
UDI per Article 27, with registration in EUDAMED.
US (FDA)
UDI per 21 CFR Part 830, with registration in the Global Unique Device Identification Database (GUDID).
Key Difference
Both systems require UDI, but the databases are separate. Devices sold in both markets need UDI registration in both EUDAMED and GUDID. The UDI format (GS1, HIBCC, ICCBBA, IFA) is generally compatible, but the database entries are separate.
Labeling and Language
EU (MDR)
Labeling per Annex I Chapter III. Instructions for Use required in the official language(s) of each Member State where the device is sold. This can mean translations into 20+ languages.
US (FDA)
Labeling per 21 CFR Part 801. English language. Single market, single language (with some exceptions for devices marketed to non-English-speaking populations).
Key Difference
US labeling is simpler from a language perspective. EU labeling is far more complex due to multi-language requirements.
Establishment and Device Registration
EU (MDR)
Manufacturer registration and device registration in EUDAMED. Authorized Representative required for non-EU manufacturers.
US (FDA)
Establishment registration and device listing with the FDA. US Agent required for non-US manufacturers. Annual registration fees apply (currently several thousand USD per establishment per year).
Strategic Implications for EU Startups
Start with the EU
MDR is generally the more demanding framework. If you build your regulatory compliance for MDR, you have a strong foundation for FDA submissions. The reverse is less true — FDA compliance does not automatically meet MDR requirements.
Clinical Evidence Advantage
Your MDR clinical evidence will often exceed FDA 510(k) requirements. This can make the US submission faster and less costly.
QMS Synergy
With the FDA's transition to QMSR (ISO 13485-aligned), a single QMS can serve both markets with minimal adaptation.
Budget for Dual Compliance
US market entry adds costs: FDA user fees (submission fees), US Agent, regulatory counsel, potentially a US-based clinical investigation. Budget EUR 50,000 - 200,000+ for a 510(k) submission (excluding clinical studies), and significantly more for PMA.
Engage US-Specific Expertise
Do not attempt FDA submissions with EU regulatory expertise alone. The FDA system has its own culture, expectations, communication norms, and strategic nuances. Engage a US regulatory consultant or regulatory affairs firm with FDA submission experience.
Tibor is straightforward: "I know EU MDR deeply. I do not know FDA deeply. And I will not pretend otherwise. When startups I work with are ready for the US market, I connect them with FDA specialists. The worst thing you can do is apply EU regulatory logic to an FDA submission — the systems look similar on paper but operate very differently in practice."
The Bottom Line
MDR and FDA regulation share a common goal — ensuring medical devices are safe and effective — but achieve it through fundamentally different systems. The EU's Notified Body conformity assessment model differs from the FDA's direct pre-market review model in philosophy, process, and practical execution.
For EU startups with global ambitions, the strategic approach is clear: build robust MDR compliance first, then leverage that foundation for US market entry with appropriate US-specific expertise. The clinical evidence, quality system, and documentation you build for MDR will carry significant value in the FDA context — but translation is required, not just transplantation.
Two markets, two systems, one device. Plan for both, but sequence wisely.