EU IVDR Class D Conformity Assessment: EURL Verification and Expert Panel Consultation

1. Key takeaways

Class D is the only class that stacks three external review layers. The first layer is the notified body assessment under Annex IX Chapters I, II (except Section 5) and III (Article 48(3)). The second layer, for device categories for which a European Reference Laboratory (EURL) has been designated, is verification by the EURL through laboratory tests of the performance claimed by the manufacturer and of compliance with applicable common specifications (Article 48(5)). The third layer is the consultation of an expert panel: where no common specifications apply and the certification is the first of its kind for that type of device, the notified body must seek expert panel consultation on the performance evaluation report (Article 48(6)). In addition, the notified body must notify the competent authorities of the Class D certificates it issues through the electronic system of Article 52, as required by Article 50(1).

The consequence is a project structure unlike any other IVDR class. Class D certification must be planned around external parties the manufacturer does not contract with directly: the EURL, whose laboratory testing consumes reference materials and batch samples, and the expert panel, whose consultation runs inside a defined transmission window. There is also a continuing obligation after certification: batch testing of production devices through the EURL under Annex IX Section 4.12 or Annex XI Section 5.1. A Class D budget that only covers the notified body quotation will systematically understate the true cost of certification and of the years that follow it.

2. Legal basis

The table below lists the primary legal sources for the Class D pathway.

3. Expert insights

Insight 1: expert panel consultation is triggered by a double absence, no common specifications plus first certification.

Article 48(6) applies where the Class D device has no applicable common specifications and the certification is the first for that type of device. Procedurally, the notified body must provide the performance evaluation report to the expert panel within 5 days of receiving it from the manufacturer, and the experts, under the supervision of the Commission, deliver their opinion within the period set for the EURL scientific opinion. Where opinions differ, Article 50(1) requires the notified body to attach a full justification to its notification. For manufacturers, the practical reading is that the performance evaluation report must be final enough to withstand expert scrutiny before the application window opens, because the 5-day transmission clock starts on receipt.

Insight 2: the focus of EURL verification is analytical and diagnostic sensitivity.

Article 48(5) states that the laboratory tests of the EURL should particularly focus on analytical and diagnostic sensitivity using the best available reference materials. The manufacturer must therefore prepare sufficient quantities of compliant reference materials and batch samples in advance and include the logistics time for sample transport in the project schedule (see article 16 of this series for details). Sample shortages or customs delays at this stage cannot be recovered elsewhere in the timeline, because the EURL calendar is external to the project and cannot be compressed by the manufacturer.

Insight 3: Article 50 is a mechanism about who gets to see the certificate, not a second approval.

Article 50(1) requires the notified body to notify the competent authorities of Class D certificates it issues (except for supplementary certificates and renewal applications), with the notification containing the instructions for use (Section 20.4 of Annex I), the summary of safety and performance (Article 29), the notified body assessment report and, where applicable, the EURL tests and scientific opinion and the expert panel opinion. Article 50(2) allows the competent authorities, and where applicable the Commission, to initiate procedures under Articles 40–43 or Article 89 on the basis of reasonable concerns and to take measures under Articles 90 and 92. The notification is thus a transparency and scrutiny mechanism rather than a separate approval step, but it means the entire assessment file is visible to authorities from day one.

Insight 4: batch testing is a continuing obligation specific to Class D.

Annex IX Section 4.12 and Annex XI Section 5.1 require samples or batches of production devices to be sent to the EURL for testing, and Article 48(13)(c) empowers the Commission to set the frequency of such testing by implementing acts. This means the cost structure of Class D retains a long-term batch testing expenditure after certification. The frequency, sample volumes and logistics should be written into the post-certification budget, and the supply of retained batches should be planned so that ongoing production is never squeezed by testing demand.

4. Practical recommendations

The following actions align a Class D project with its three-layer structure.

1. At project start, confirm whether the product category already has a designated EURL, with 6 categories designated in total under (EU) 2023/2713 and (EU) 2025/2526, and use this to determine whether the second layer is triggered.
2. Confirm whether any common specifications apply ((EU) 2022/1107), which determines whether the third layer of expert panel consultation is triggered.
3. Stock reference materials, reference substances and batch samples early and schedule logistics and testing time separately in the project plan.
4. Finalise the performance evaluation report ahead of the Article 48(6) requirements and reserve the 5-day transmission window.
5. Agree with the notified body on the division of responsibility for preparing the Article 50(1) notification material (summary of safety and performance, instructions for use, assessment report).

5. Verification checklist

Confirm the following points before and during a Class D project.

• □ The Class D main route (Annex IX Chapters I, II except Section 5, and III) or alternative route (Annex X plus XI) has been confirmed
• □ Whether the product category has a designated EURL has been confirmed (determines whether Article 48(5) is triggered)
• □ Whether applicable common specifications exist has been confirmed (determines whether Article 48(6) expert panel consultation is triggered)
• □ Reference materials, batch samples and logistics have been scheduled
• □ The performance evaluation report reserves the 5-day transmission window under Article 48(6)
• □ The Article 50(1) notification material list has been agreed with the notified body

Regulatory information verified as of October 29, 2026.

GRZAN supports IVD manufacturers in the EU market with CE certification pathway and classification strategy under Regulation (EU) 2017/746. For Class D programmes we help you map EURL and common specification triggers, prepare performance evaluation reports for expert scrutiny, plan reference material logistics and budget ongoing batch testing. Contact us at info@grzanglobal.com to discuss your EU IVDR programme.