MDD vs. MDR: Key Differences for Medical Devices

(And Why It Matters for Medical Devices in Europe)

Before any medical device — such as a surgical instrument, disinfection equipment, or heart monitors — can be used in a hospital or sold in Europe, it has to follow strict rules to make sure it’s safe and works properly.

In Europe, there used to be an old set of rules for checking medical devices. These old rules were called the MDD (Medical Device Directive - Directive 93/42/EEC). Now, there are new and much stricter rules called the MDR (Medical Device Regulation, 2017/745 MDR).

What Was the MDD?

The MDD (Directive 93/42/EEC) was a helpful guide for companies. It said, “Here’s how you should check your medical devices.” But companies could decide how to follow it, and it didn’t always ask for strong proof that each device worked safely.

That worked fine years ago, but medical technology has gotten much more advanced — and more complex — so the old rules just weren’t enough anymore.

So, the MDD was replaced by something stronger: MDR.

MDR is not a suggestion — it’s the law.

What Is the MDR?

The MDR is the new law (Regulation (EU) 2017/745) for all medical devices in the European Union. It started in 2017, and every company had to follow it by May 26, 2021.

The big difference? MDR is not a suggestion, it’s the law. Every company must follow it exactly.

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Why Is MDR Better?

Here are the big changes MDR brought:

‍1. Safer Products
Medical devices now need to go through more tests before and after they’re sold to make sure they are safe for patients, not just once, but throughout their lifetime.

‍2. Better Tracking & Transparency
‍Companies must keep very clear records about each device, so if there’s ever a problem, they can fix it quickly or pull it off the shelves.

3. Covers More Devices
The new rules now apply to an even wider range of medical products, that were previously not covered.

‍4. Stricter oversight by Notified Bodies‍

Special organizations (called Notified Bodies) perform in-depth evaluations to ensure compliance by requesting comprehensive technical documentation to make sure they’re following the law properly.

What’s Happening Now?

Even though MDR started in 26 May 2021, companies have some extra time to update their old products. They can keep selling devices under the old MDD rules until the end of 2028, but only if they:

Have a signed agreement with a Notified Body to transfer the product from MDD to MDR.
Passes a surveillance audit under ISO 13485:2016 — this is an international quality standard that checks whether the company’s processes for designing, making, and managing medical devices are working properly and safely.
Have met these requirements before September 26, 2024 — this is a hard deadline. Failing to meet this deadline will result in the invalidation of the MDD certificate.

A company must obtain a Confirmation Letter from its Notified Body to show that its MDD certificate is still valid. Without that letter, it won’t be allowed to continue selling those products under the old MDD Directive.

Why This Matters

The MDR rules help make sure medical devices are safer, better tested, and more carefully watched over by Notified Bodies. This gives doctors, patients, and hospitals more confidence that the devices they use really work — and won’t cause harm.

April 15, 2025