EU IVDR Class C Conformity Assessment: Generic Device Groups and Companion Diagnostics

1. Key takeaways

Class C devices must follow Chapters I and III of Annex IX, with a technical documentation assessment of at least one representative device per generic device group under Sections 4.4 to 4.8 (Article 48(7)). Three situations tighten the route. First, self-test and near-patient devices add an assessment under Section 5.1. Second, companion diagnostics must, for every single device, go through the Sections 4.1 to 4.8 assessment and be consulted with the competent authority or the EMA under Section 5.2. Third, the manufacturer may switch to the combination of Annex X and Annex XI (excluding Section 5 of Annex XI) under Article 48(8).

Class C is where most molecular diagnostic and oncology product lines land, because Rule 3 of Annex VIII lists thirteen Class C intended purposes, including detection of sexually transmitted agents, cancer screening and diagnosis, human genetic testing, companion diagnostics, therapeutic drug monitoring and screening for congenital disorders in newborns. The cost lever in this class is the generic device group: one representative device can carry the assessment conclusions for every device in the group, which is the core instrument for controlling the number of assessments and the fees. Defining and defending those groups, and identifying companion diagnostics early so their individual assessment and consultation timeline can be planned, are the two management priorities of any Class C programme.

2. Legal basis

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

3. Expert insights

Insight 1: the generic device group is the cost valve of Class C.

Article 2(8) defines a generic device group as a set of devices having the same or similar intended purpose or a commonality of technology allowing them to be classified generically. Sharing the assessment conclusions of one representative device across the group is the central mechanism for controlling the number of assessments and the cost of a Class C project. The grouping argument should cover intended purpose, analyte, methodology, sample type and the way results are interpreted. A group defined on intended purpose alone but spanning different chemistries is vulnerable; a group supported on all five dimensions is difficult for a notified body to dismantle. The grouping map, once confirmed in writing, becomes the backbone of the certificate scope.

Insight 2: companion diagnostics in Class C receive no sampling treatment.

The third subparagraph of Article 48(7) requires companion diagnostics to go through the technical documentation assessment under Sections 4.1 to 4.8 for each device, with consultation under Section 5.2 with the competent authority or the EMA. In other words, the one-per-group sampling rule does not apply to companion diagnostics, and neither does the alternative route relief of Article 48(8), which still requires device-by-device consultation. Manufacturers of diagnostic platforms that include companion diagnostic claims must therefore budget a full individual assessment for each such product, in addition to the medicinal product consultation timeline. This is the single largest schedule driver in Class C portfolios containing companion diagnostics.

Insight 3: the thirteen Class C intended purposes cover the categories where IVD exporters concentrate.

The thirteen intended purposes of Rule 3 of Annex VIII (set out in detail in article 04 of this series) include detection of sexually transmitted agents, cancer screening, diagnosis and staging, human genetic testing, companion diagnostics, therapeutic drug concentration monitoring and screening for congenital disorders in newborns. Most molecular diagnostic and tumour marker product lines fall into Class C, which makes it the class that IVD exporters need to schedule earliest. Understanding that a single product platform may serve several Rule 3 purposes, and that each purpose drives the class determination, helps avoid under-classification errors that surface late during notified body review.

Insight 4: the alternative route of Annex X plus Annex XI is not a bypass of assessment.

Article 48(8) allows Class C to switch to Annex X type-examination plus Annex XI production quality assurance (excluding Section 5), but companion diagnostics must still be consulted device by device (point (k) of Section 3 of Annex X). Type-examination concentrates preparation requirements on the specimen and the examined batches, which suits product lines with converging models and stable batch production. The route does not reduce the scientific evidence burden; it reorganises it around a type examined once and production quality verified continuously. The choice should be evaluated against the manufacturing footprint before the application is filed.

4. Practical recommendations

The following actions structure a defensible and cost-controlled Class C project.

1. Build a generic device group map along four dimensions, intended purpose, methodology, analyte and sample type, and obtain written confirmation from the notified body.
2. Document in writing why each representative device represents the worst case of its group, so the selection survives review.
3. For companion diagnostics, move the EMA or competent authority consultation node under Section 5.2 to the front of the project plan and estimate the timeline in quarters rather than months.
4. For self-test and near-patient Class C products, prepare the Section 5.1 documentation as a separate volume.
5. If the Annex X plus XI route is chosen, first clarify how the production quality evidence chain is completed after the exclusion of Section 5 of Annex XI.

5. Verification checklist

Confirm the following points before filing a Class C application.

• □ The applicability of Annex IX Chapters I and III has been confirmed under Article 48(7)
• □ Generic device groups have been defined under Article 2(8) with at least one representative device per group
• □ The worst-case justification for each representative device has been documented
• □ Companion diagnostics have been confirmed for device-by-device assessment plus EMA or competent authority consultation (Section 5.2)
• □ Self-test and near-patient products have been supplemented with documentation per Section 5.1
• □ The feasibility of the alternative route (Annex X plus Annex XI, excluding Section 5 of Annex XI) has been evaluated

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 C portfolios we help you build generic device group maps, document worst-case justifications, plan companion diagnostic consultations and evaluate the Annex X plus XI alternative. Contact us at info@grzanglobal.com to discuss your EU IVDR programme.