FDA & MDR: The Real Difference of Medical Device Risk Classes
Let’s face it: in MedTech it always comes down to proving your product is both safe and effective. Period. To do that, you must precisely identify which of the medical device risk classes your product applies to. These classifications are dictated by specific authorities, which differ for each region – such as the Japanese PMDA, Health Canada or the U.S. FDA and EU MDR. In this article we will focus on comparing the latter two and answer some burning questions: What do you need to prove to pass the regulatory assessment and how precise do you need to be when determining a risk class?
The Safety Foundation: What Are Medical Device Risk Classes?
When your health or even your life depends on a device, you certainly want to be assured that it is safe. So, how to prove a device is safe to use? Let’s break it down.
This chain reaction of safety must occur in every medical device development process.
While this process must always begin with defining the product’s intended use, the true regulatory turning point is classification. Miscategorizing your device can trigger irreversible financial and time consequences. After setting the ultimate definition, take your time and assign the correct risk class to your product.
Medical device risk classes are specific “shelves”, determined by regulatory authorities, where you must put your product in. Only with an assigned class you know exactly which legal requirements are obligatory for your device, which tests it must pass to meet specific standards, and ultimately, how to get it certified. In both cases – the FDA and MDR – having a proper certificate is not an addition, it is a legal must. Furthermore, classes determine not only every regulatory stage, but also the needed budget (e.g. for specific clinical tests).
So, what is the difference between the FDA and MDR approach?
FDA vs. MDR: The 5 Key Differences Between Them
Let’s start with the basics: names and regions. The Food and Drug Administration (FDA) is a federal agency of the United States government that protects public health by ensuring the safety, efficacy and security of medical devices and other related products. The European Union Medical Device Regulation (MDR) is the strict legal framework that controls the safety, manufacturing, and distribution of medical tools across Europe.
Both institutions are crucial for introducing any medical device to the U.S. or EU market. Choosing between the FDA and MDR not only dictates which region will receive your solution, but it is also a huge business decision that impacts essential requirements, regulatory path, and the order of steps to follow for entering the market.
Medical Device Risk Classes’ Chain Reaction of Safety.
Taking a closer look at both, there are 5 key differences:
- Regulatory Structure and Costs
FDA
The FDA is a single, centralized regulatory authority. This structure provides consistency and predictability in decision-making. Moreover, costs are easily accessible, because they are published upfront.
MDR
The MDR has a decentralized system, where rules are created by multiple Notified Bodies (NBs). It results in variable efficiency and interpretation of the law may differ. Costs depend on the specific NB’s offer, which may fluctuate significantly even if the medical device risk classes are the same. So always have at least 3 different offers from NBs and try to avoid the trap of pricing: the most expensive offer doesn’t have to be the best one for your product.
- Audits
FDA
The FDA’s audits are highly formalized, featuring official question-and-answer sessions and the influence of the government. They used to require compliance with 21 CFR Part 820, however they are currently harmonizing their QMS with the ISO 13845 standard.
MDR
Audits by Notified Bodies occur in two stages: the first focuses on QMS (ISO 13485), and the second dives deep into the device’s technical documentation. It is all conducted directly by accredited private entities.
- Equivalence and Clinical Evidence
FDA
In the U.S. institution, there is great flexibility when it comes to clinical evidence. They often allow earlier market access even with limited data, especially in innovation programs, only under the condition that real-world evidence will be gathered post-market. Additionally, they offer a special Humanitarian Device Exemption (HDE) program for rare diseases affecting fewer than 4000 patients.
MDR
Introducing a product based solely on a previously accepted device used to be common in the EU, under the MDR it is now rare. It is caused by obligatory, proven similarities in technical, biological, and clinical aspects, which is often only possible if you have legal access to the competitor’s technical documentation. Because of the process being more rigorous, the EU frequently demands entirely new clinical trials and post-market surveillance.
- Certification Lifecycle
FDA
The certification path consists of implementing a QMS, classifying the device, choosing the correct regulatory pathway (such as 510(k), PMA, or De Novo), conducting verification and validation, and compiling technical documentation. After all that, you submit the application to the FDA, register your establishment, designate a U.S. agent, and list the device. A huge advantage in the FDA certification process is that approvals generally do not have an expiration date.
MDR
A CE mark under the MDR is valid for a maximum of 5 years and must be renewed. To get the certificate the pathway is somewhat similar, but there is no need to choose the proper regulatory pathway, because only one exists. You must undergo a Notified Body audit, then if it is successful, the NB issues a certificate that allows you to sign the Declaration of Conformity.
- Risk classes
The last but not least difference between the FDA and MDR, is directly related to the medical device risk classes and because they dictate every other difference – let’s dive into them a little deeper.
Medical Device Risk Classes
Assigning a risk class dictates the rigorousness of your regulatory pathway. Both regulatory institutions rely on risk-based classification systems, but structure them differently. The FDA uses three classes (I, II, III), whereas the MDR uses four (I, IIa, IIb, III). While the numbers and example devices are pretty much comparable at a glance, dig a little deeper and you see an impactful difference: risk analysis is indicated by different ruling systems that put your product in the correct “shelf” of medical device risk classes.
The classification process occurs differently in each institution. The FDA categorizes different types of devices into 20 specialty panels by their intended use and three-letter product codes. The Product Classification Database groups devices by name, clinical tests, application type and whether they sustain life. Interestingly, under one regulation, devices can have different codes and classes (e.g. a manual stethoscope with LDE code is Class I, while electrical, DQD, one is Class II).
On the other hand, the MDR uses the 22-rule classification system, which is described in detail in Annex VIII. They take into account factors such as the duration of usage, whether the device is invasive or active, and other special functionalities. You must conduct the classification by yourself using these rules and prove it in the technical documentation.
What Are the Types of Medical Device Risk Classes?
How do medical device risk classes actually look like in the FDA versus the MDR?
- Class I
This class is defined by both institutions as low risk and includes basic tools like simple adhesive bandages. It is the simplest and cheapest group, which is not so rigorous and time-consuming.
FDA
In the U.S., Class I medical devices present minimal risk. They require just general controls, and most of them do not have to pass complex premarket procedures. According to FDA, Class I medical devices can be additionally categorized as “with exemptions” or “without exemptions”.
MDR
Under EU standards, this class allows developers to issue a declaration of conformity by themselves. Furthermore, Class I medical devices in the EU can be subcategorized into:
- Class Is (sterile)
- Class Im (with measuring function)
- Class Ir (reusable)
Unlike standard Class I devices, these specific subcategories must come alongside with a limited Notified Body involvement.
- Class II
FDA
This moderate-risk class covers devices like hearing aids or orthodontic brackets. They require not only general controls but also special ones and, much like the level below, Class II medical devices can also be with or without exemptions.
- Class IIa
MDR
In the MDR there are two separate categories instead of just one Class II. The MDR Class IIa is a low-to-moderate risk class that includes devices like infusion sets or minor clinical software. Here, the invasive characteristics usually begin, so because of that, the Class IIa requires Notified Body to conduct a full QMS audit and a technical documentation review.
- Class IIb
MDR
The next MDR class before the highest risk one is the IIb category. This class has a higher-moderate risk than IIa. Class IIb medical devices include respirators, infusion pumps or non-therapeutic, life-monitoring devices. The IIb class often requires not only a NB assessment, but also clinical trials.
- Class III
This is the highest risk class achievable in both the FDA and MDR, yet they still are a bit different. For example, most joint endoprostheses in the EU are automatically Class III while in the U.S. many are still considered Class II.
FDA
Class III FDA devices include ones that sustain life or present a high potential for injury, such as pacemakers or Automated External Defibrillators (AEDs). Class III in the FDA requires both general controls, as well as, an expensive Premarket Approval (PMA).
MDR
The MDR high-risk class includes tools like implants, stents, or even AI-driven clinical decision support systems. Here, clinical trials are always mandatory, alongside a full QMS audit, technical documentation evaluation, and strict post-market surveillance.
Why You Can’t Directly Translate FDA to MDR?
“My device is Class II in the US, so it must be Class II in the EU as well”. That is one of the most common misconceptions in the MedTech industry.
Software as a Medical Device (SaMD) is a perfect example. A standalone software might be a simple, low-risk Class I in the USA, but under the MDR, AI systems supporting clinical decisions are strictly classified as Class III (highest risk). Furthermore, innovative software in the US often requires a mandatory pre-submission dialogue with the FDA to catch risks and misunderstandings early.
Yes, medical device risk classes might seem similar at first glance – they do have almost the same names, after all. Yet, they present different philosophies. Unfortunately, many developers think that mapping them 1:1 is acceptable. Due to misunderstandings like this, in the U.S. alone, 32% of 510(k) submissions are rejected at the very first stage, mainly because of:
- ignoring thorough analysis of the predicate device,
- failing to realize that a late-stage design modification alters the device’s classification,
- self-classifying without properly checking FDA databases.
Assuming that succeeding in one region automatically guarantees an easy path in the other one is a critical trap. Each market demands a tailored, specific regulatory strategy from the outset. Understanding medical device risk classes is a strategic decision that shapes your budget, timeline, and business success.
Whether you choose to launch with the FDA or the MDR first, partnering with experienced experts to navigate this complex regulatory maze ensures your innovation safely reaches patients without unexpected changes.
Summary
Whether you choose to launch with the FDA or the MDR first, partnering with experienced experts to navigate this complex regulatory maze ensures your innovation safely reaches patients without unexpected changes.
If your team is looking for a partner to smoothly navigate regulatory hurdles for a new medical device – we are here to help!
Source:
https://fda.yorkcast.com/mediasite/Play/17792840509f49f0875806b6e9a1be471d
https://www.sciencedirect.com/science/article/pii/S0020138323005946
MedTech Startup Academy Webinar (2025): “MDR czy FDA? Regulacyjne ścieżki innowacji – porównanie i wnioski”. Presented by Paweł Jurijków.
