Regulatory Affairs gets questions about regulatory compliance, technical documents, registration requirements, and more during product development.

Most of these discussions boil down to one question:

Why does this matter?

The way you group your portfolio dictates:

• how many technical files you compile

• how many design variants and product lines you maintain

• how much testing you pay for

That grouping decision sets the resources you invest for launch and sustaining.

It also affects how you register your devices.

If you group devices smartly, you save time, effort, and money.

Companies try to bundle as many devices as possible into one family.

Both China and the EU allow you to group devices, but they don’t define those groups in the same way.

In this series, I’ll break down how NMPA groups medical devices, and how that differs from the EU.

🍜 Product Grouping in China

If you read my newsletter on China’s 2025 UDI draft, you’ll know that China doesn’t talk about “Basic UDIs” at all.

In China, the buzzword is “registration unit”.

Put simply: one registration unit equals one NMPA certificate.

One set of a complete submission package of type testing, clinical evaluation, design control, and V&V evidence to get a single NMPA licence.

NMPA defines registration units based on four main criteria:

• Technical principle

• Structural composition /component

• Performance indicator / essential performance

• Scope of application / intended use

Different rules apply to active devices, non-active devices, and IVDs. Here, I’ll stick to medical devices and leave IVDs aside.

So how does NMPA actually group devices in each category?

🍜 Active Devices

For active devices, NMPA focuses on technology and system architecture.

Common differences that trigger separate registration units include:

Technical Principle
Different modes of action or technical principles. Example: electrochemical vs optical blood glucose meters.

Key Structure
Same technical principle, but differences in key structure or components that affect safety or effectiveness.

Performance Indicator
Differences in performance parameters that change the scope of application or mechanism of action.

Intended Use
Same technical principle and key composition, but different intended uses.

Broad, “creative” intended uses won’t help much.

NMPA’s product catalog already links the intended use to a device group and risk level. You can’t outsmart that.

If active devices share the same intended use and work together, but can still function independently, NMPA usually treats them as separate registration units.

However, active device accessories connected to the main console usually fall under one registration unit.

Let’s talk if you need support defining your grouping strategy for China.

🍜 Non-active Devices

For non-active devices, the technical principle is crucial, but other criteria get trickier. Here’s how they look at it.

Product Composition

Devices that contain medicinal substances or active ingredients (API) cannot sit in the same registration unit as devices that don’t.

The same applies if devices have different surface treatments or physical properties, such as different coatings or material types.

Even if devices share the same key composition and intended use, NMPA may still split them if unique characteristics affect safety or effectiveness.

Performance Indicator

NMPA expects separate registration units when you have:

• Different product composition or processing treatments

• Single-use vs reusable devices with varying performance metrics

• Devices sterilized with different methods of sterilization

• Differences in key structures that affect intended use and/or performance requirements

If the raw materials come from different biological origins, you must register devices separately.

Intended Use

This follows the same logic as active devices. Also, you should separate devices with different methods of application or target anatomical sites.

You can register a set of instruments together if you use them in combination to achieve the same surgical purpose.

🍜 Key Differences Between EU and China

 Core Concept

The EU doesn’t use the “registration unit” concept.

Under MDCG 2018-1, all devices under one Basic UDI-DI share the same intended purpose, risk class, and essential design and manufacturing characteristics.

Article 2(7) of EU MDR defines a generic device group as:

The Basic UDI-DI is much stricter than a generic device group.

Even though MDCG guidance is not legally binding, it’s the guiding light for manufacturers and Notified Bodies.

You need a Basic UDI-DI for EUDAMED and MDR technical documentation. One MDR certificate can cover multiple device families

China works differently.

NMPA has defined a list of product categories with intended use.

Each registration unit defines the ”narrowed” scope of the device covered by a single NMPA certificate.

Manufacturers file separate submissions and receive multiple certificates for different scopes.

Criteria of Product Grouping

MDR applies the same Basic UDI logic across all device types.

The EU MDR and MDCG 2018-1 focus heavily on the intended use when assigning UDI:

• New UDI-DIs

  When you make changes in models, sterility, warnings, or pack quantities.

• New Basic UDI-DIs

  Changes to the intended purpose, risk class, major design, or manufacturing process

The EU keeps the grouping logic, high-level and principle-based. This gives you more flexibility.

China takes a more technology-centric approach and focuses strongly on technical principles and product structures.

Intended use still matters a lot, but it does not override the technology.

In the EU, there’s no UDI rule that forces you to split groups purely by technology type (e.g. active vs non-active).

China not only draws that line, but also gives specific examples of devices that must be split into separate registration units.

For example, you should register MRI, CT, X-ray, patient monitors, ECG machines, endoscopes, and laser therapy devices separately.

So a manufacturer with a modular “system” under one Basic UDI-D may need to split those modules into several NMPA registration units in China.

Variants and Model Specifications

Within one Basic UDI-DI, all devices share the same intended purpose, risk class, and essential design and manufacturing characteristics.

This means devices with different sizes, minor design tweaks, or configuration options usually sit together as variants under the same Basic UDI-DI, each with its own UDI-DI.

For example, implants or catheters with different lengths or colours can typically stay in a single family.

China’s NMPA definition of a registration unit further restricts the scope more than the Basic UDI-DI.

One registration unit only applies if the scope of application, performance, and structure are identical.

NMPA will expect separate registrations if there are additional differences in structural design or materials, such as coatings on the stent.

That’s it for now on EU vs China product grouping. Hope this helps you map your portfolio and be more prepared for China.

Need help assessing your regulatory approach for the China registration? Let’s talk!

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Disclaimer: This content is created solely in my personal interest and does not reflect the views, opinions, or policies of my employer or any other organizations I am affiliated with. Neither I nor my employer is liable for any use of this content. This newsletter does not compete with my employer’s interests. Any references to regulatory updates or guidance are based on publicly available information and are not intended to infringe upon proprietary or confidential content.