Custom-made medical devices are the odd one out when it comes to the Medical Devices Regulation (EU) 2017/745.
The MDR mentions “other than custom-made devices” 10 times and “other than custom-made devices” 1 time. Moreover, a specific annex to the MDR is dedicated to custom-made devices (Annex XIII).
In this article, we will explain
- why this is the case,
- what is included in the definition of custom-made medical devices,
- and what that means in practice for your devices specifically (highlights and areas of focus).
What does “custom-made” mean according to the MDR?
The regulation quotes the following:
‘custom-made device’ means any device specifically made in accordance with a written prescription of any person authorised by national law by virtue of that person’s professional qualifications which gives, under that person’s responsibility, specific design characteristics, and is intended for the sole use of a particular patient exclusively to meet their individual conditions and needs.
However, mass-produced devices which need to be adapted to meet the specific requirements of any professional user and devices which are mass-produced by means of industrial manufacturing processes in accordance with the written prescriptions of any authorised person shall not be considered to be custom-made devices;
If you’re reading this as a manufacturer, it seems like quite a gray area. Especially the second paragraph is confusing.
Guidance by the IMDRF and MDCG
Fortunately, in March 2020 and March 2021, respectively, the IMDRF (International Medical Device Regulators Forum) and the MDCG (Medical Device Coordination Group) wrote a number of guidance documents:
- The IMDRF wrote the “Personalized Medical Devices – Regulatory Pathways”;
- and the MDCG wrote the “MDC 2021-3 Questions and Answers on Custom-Made Devices”.
The IMDRF provides more detail on the differences between custom-made, patient-adapted, and custom-made devices. See their handy decision tree below:

Figure 1 – IMDRF‘s decision tree concerning the differences between custom-made, patient-adapted, and customizable devices
The MDCG refers to the IMDRF document and addresses the questions raised therein, but rather attempts to parse the definition of the MDR and provides concrete examples.
These two tools should give you a good idea of how your product can be defined. And if any doubts remain, the Notified Body or Competent Authority can be consulted.
Why are custom-made medical devices the odd man out?
Why do custom-made medical devices seem so different from other devices in the MDR? Under the Medical Device Directive (MDD), newer technologies such as additive manufacturing and subtractive manufacturing were not covered and could remain under the regulatory radar.
The upside of this was that many patients with very specific needs received tailored and personalized care. The downside was that high-risk implantable devices were also not covered by the regulations, with all the risks this entailed for the patient.
So what was the goal of the MDR? To be able to cover these patient-specific and custom-made devices from a regulatory standpoint, but not to cause a decrease in production or the number of manufacturers for these patients.
Because after all, for many of these patients, there are no other alternatives. And then it comes down to whether the benefit outweighs the risks.
What do you need to have in place as a custom-device manufacturer?
What is NOT needed?
While non-custom-made devices all require technical documentation (Annex II and Annex III of the MDR) including clinical evaluation, custom-made devices are exempt from this.
This is to prevent a non-mass-produced device from requiring a lot of work and manufacturers being reluctant to develop custom devices.
What IS needed?
This does not mean that they are exempt from other regulations. Annex XIII of the MDR is specifically devoted to custom-made medical devices.
The main point of this annex is that the manufacturer must think carefully about the prescriber and his qualifications.
He must consider the traceability of the device: document information about the design, manufacturing process, and performance of the device and take steps to ensure that the manufacturing process is as specified.
And the manufacturer should also consider documenting experience gained in the post-production phase.
Serious incidents and corrective actions related to field safety must be communicated to the competent authorities.
A statement as referred to in Annex XIII must be prepared, updated, and remain available to the competent authorities and to the specific patient or user for whom the device is made.
Additional specifics for class III custom-made implantables
As mentioned earlier, high-risk custom-made medical devices were the main concern of regulators. To address these risks, regulators added an additional requirement for Class III custom-made implantable devices. Namely in the conformity assessment, they must follow.
In addition to Annex III with which they must comply:
- They must also follow a conformity assessment in accordance with Annex IX, Chapter I, or Annex XI, Part A.
- Annex IX, Chapter I, requires them to have a quality management system.
- Annex XI, Part A, requires production quality assurance.
Extra tips to remember
- Custom-made devices do not need to be covered by the UDI system. But note that they still need to be traceabe by using a code, for example;
- Registration in EUDAMED is not required;
- Custom-made devices require a Statement (see above, Annex XIII, section 1), but not a Declaration of Conformity;
- Custom-made devices are not CE marked;
- Make sure to have a list of all custom-made devices in case the competent authority asks for it (sold in their territory);
- Add the words ‘custom-made device’ on the label;
- And finally, never forget your device classification. Just because the device falls under the definition of ‘custom-made’ does not mean it is exempt from classification. You still need to provide a classification rationale, along with an explanation of why the device is custom-made. This will result in a Class I custom-made; Class IIa custom-made; Class IIb custom-made or Class III custom-made medical device.
Conclusion
Custom-made medical devices were not covered by the Medical Devices Directive, which resulted in devices coming onto the market that were not controlled by the regulations and could have led to patient harm.
In response, EU regulators wanted to address these issues in the new Medical Device Regulation 2017/745, without reducing the number of custom-made devices on the market (due to overly burdensome regulatory requirements).
They dedicated an entire annex to these devices, making the regulations stricter than before, but manageable.
For custom-made medical devices, the regulation provides some tools, but other new technologies are emerging, which will require regulators to overcome new hurdles.
Do you need help getting your device to meet the requirements of the MDR? Our experts have years of experience with custom-made medical devices. We are happy to help!