Under the European Medical Device Regulation (EU) 2017/745 (MDR), manufacturers are required to prepare technical documentation demonstrating the conformity of their medical devices with the applicable regulatory requirements. A frequently asked question from manufacturers is whether a single technical documentation file can include multiple devices.

The MDR does not specify a numerical limit for the number of devices that can be included in one technical documentation. Instead, the acceptability of grouping multiple devices in one file depends on whether the devices belong to the same device family and share common characteristics.

In practice, the number of technical documentation files prepared under MDR is also an important strategic consideration for manufacturers. Each technical documentation file submitted to a Notified Body typically requires a separate assessment during the conformity assessment process. Since MDR certification has become significantly more resource-intensive compared to the previous regulatory framework, the number of technical documentation files may directly influence certification costs and review timelines. For this reason, many manufacturers try to group device variants within the same device family into a single technical documentation file when it is scientifically and regulatorily justified.

Regulatory Basis

The structure and content of technical documentation are defined in Annex II and Annex III of Regulation (EU) 2017/745. These annexes describe the documentation required to demonstrate device safety, performance, and compliance with the General Safety and Performance Requirements (GSPRs).

Although the MDR does not explicitly define the maximum number of devices allowed in a single technical documentation, the concept of device families and Basic UDI-DI grouping provides the regulatory framework for determining appropriate grouping. Manufacturers preparing technical documentation under MDR must ensure that device grouping is properly justified.

Device Family and Basic UDI-DI

According to MDCG 2018-1 guidance on UDI assignment, the Basic UDI-DI is the primary identifier used to group medical devices with the same intended purpose, risk class, and essential design and manufacturing characteristics.

Devices can generally be included in the same technical documentation when they share:

• The same intended purpose

• The same risk class

• Similar design and manufacturing principles

• Comparable performance characteristics

• The same Basic UDI-DI grouping

In practice, this means that a technical documentation file may cover multiple variants of a device within the same product family.

Examples of Acceptable Grouping

Typical examples where multiple devices may be included in a single technical documentation include:

• Devices with different sizes or dimensions (e.g., catheters with varying lengths or diameters)

• Devices with minor design variations that do not affect the intended purpose or performance

• Product variants that share the same materials, manufacturing processes, and risk profile

In such cases, clinical evaluation, risk management, and verification activities can often be performed collectively for the entire device family.

When Separate Technical Documentation May Be Required

Separate technical documentation may be necessary when devices differ significantly in one or more of the following aspects:

• Intended purpose

• Mode of action or operating principle

• Risk classification

• Sterilization method

• Materials that may affect biological safety

• Performance characteristics requiring different clinical evidence

Notified Bodies typically expect manufacturers to justify the grouping of devices within a single technical documentation file. The rationale should clearly demonstrate that the devices belong to the same device family and that the supporting evidence is applicable to all included variants.

Practical Considerations

When preparing technical documentation covering multiple devices, manufacturers should ensure that:

• Device variants are clearly defined and traceable

• The scope of the device family is justified

• Risk management activities address all variants

• Clinical evidence supports the entire device family

• The Basic UDI-DI grouping is consistent with the documentation structure

A well-structured technical documentation file not only supports regulatory compliance but also facilitates efficient review by Notified Bodies during conformity assessment.

Conclusion

The MDR does not impose a strict limit on the number of devices included in one technical documentation. Instead, grouping is determined by the device family concept and Basic UDI-DI assignment. When devices share the same intended purpose, risk class, and essential design and manufacturing characteristics, they can generally be documented together within a single technical file.

However, manufacturers must ensure that the grouping is properly justified and that the technical documentation adequately demonstrates compliance for all included device variants.