IVDR Classification: How Annex VIII Decides Class A to D
Updated: Aug 30
IVDR classification is where most in vitro diagnostic programmes are won or lost, because everything downstream is decided by it: the conformity assessment route, whether a notified body is involved at all, whether an EU reference laboratory tests your device, and which transitional deadline applies. Under Directive 98/79/EC the Commission put notified body involvement at about 8 % of more than 40 000 IVDs on the EU market. Under Regulation (EU) 2017/746 it estimates around 80 %.
Why IVDR classification starts with the intended purpose
Article 47(1) divides devices into classes A, B, C and D, taking into account the intended purpose and the inherent risks, with classification carried out in accordance with Annex VIII. Section 1 of Annex VIII then gives ten implementing rules, and rule 1.1 governs everything: application of the classification rules shall be governed by the intended purpose of the devices. MDCG 2020-16 rev.4 restates this bluntly — unless otherwise specified, the rules apply equally to all technologies, principles of detection and analytical procedures. IVDR classification is therefore an exercise in drafting a precise intended purpose, not in describing a platform.
The remaining implementing rules do the structural work. Rule 1.2: where a device is intended to be used in combination with another, the rules apply separately to each. Rule 1.3: accessories are classified in their own right. Rule 1.4: software that drives a device or influences its use falls in the same class as that device, but software independent of any other device is classified in its own right. Rule 1.5: calibrators take the class of the device. Rule 1.6: control materials with quantitative or qualitative assigned values take the class of the device. Rule 1.10: each rule applies to first line, confirmatory and supplemental assays alike.
Two rules are constantly conflated and they are not the same. Rule 1.8 deals with multiple intended purposes — where a manufacturer states several and the device falls into more than one class, the higher class applies. Rule 1.9 deals with multiple rules — where several classification rules apply to the same device, the rule resulting in the higher classification applies. MDCG 2020-16 rev.4 adds the commercial consequence: where several rules or sub-rules apply, the intended purpose and claims must be specified well enough to allow a clear attribution, and ambiguous claims may lead to higher classification.
Rule 1 and Rule 2: the class D triggers
Rule 1 classifies as class D devices intended for three purposes, and the third indent is the one most often missed. The first is detection of the presence of, or exposure to, a transmissible agent in blood, blood components, cells, tissues or organs, or any of their derivatives, in order to assess suitability for transfusion, transplantation or cell administration. The second is detection of the presence of, or exposure to, a transmissible agent causing a life-threatening disease with a high or suspected high risk of propagation. The third is determining the infectious load of a life-threatening disease where monitoring is critical in the process of patient management — which places viral load assays in class D in their own right, not in class C under Rule 3.
Rule 2 works the opposite way round from how it is usually summarised. Devices for blood grouping, for determining foeto-maternal blood group incompatibility, or for tissue typing to ensure immunological compatibility of blood, blood components, cells, tissue or organs intended for transfusion, transplantation or cell administration are class C — except where intended to determine the markers of the ABO system, the Rhesus system, the Kell system (KEL1), the Kidd system (JK1, JK2) or the Duffy system (FY1, FY2), in which case they are class D. The listed systems are the exception, and the exception is the higher class. Reading Rule 2 the other way round is the single most common IVDR classification error in blood establishment products.
One drafting point matters if you are working from an old copy of the Regulation. The words “or to determine foeto-maternal blood group incompatibility” were inserted into Rule 2 by the corrigendum published in OJ L 334 of 27 December 2019. A file citing the original 2017 Official Journal text of Annex VIII is citing an uncorrected version.
Rule 3: thirteen sub-rules that catch most of the market
Rule 3 assigns class C and runs from point (a) to point (m). Detection of, or exposure to, a sexually transmitted agent. Detection of an infectious agent in cerebrospinal fluid or blood without a high or suspected high risk of propagation. Detection of an infectious agent where an erroneous result carries a significant risk of death or severe disability to the individual tested, to a foetus or embryo, or to the individual's offspring. Pre-natal screening of women to determine immune status towards transmissible agents. Determining infective disease status or immune status where an erroneous result would lead to a patient management decision resulting in a life-threatening situation.
Then: use as companion diagnostics; disease staging where an erroneous result would lead to a life-threatening patient management decision; screening, diagnosis or staging of cancer; human genetic testing; monitoring levels of medicinal products, substances or biological components where an erroneous result would lead to a life-threatening patient management decision; management of patients suffering from a life-threatening disease or condition; screening for congenital disorders in the embryo or foetus; and screening for congenital disorders in new-born babies where failure to detect and treat could lead to life-threatening situations or severe disabilities.
Note two asymmetries. Cancer under point (h) is unqualified — screening, diagnosis or staging, with no erroneous-result test to satisfy — whereas disease staging generally under point (g) is risk-qualified. And companion diagnostics under point (f) has a boundary that MDCG 2020-16 rev.4 draws firmly: a companion diagnostic must be essential for the safe and effective use of a corresponding medicinal product, with a link to a product identified by INN. Devices intended for monitoring treatment to keep a concentration within the therapeutic window are not companion diagnostics, and neither are devices used only for dosing in patients already determined eligible. Annex 2 of the guidance gives the decision flowchart.
Rules 4 to 7: self-testing, general laboratory use and the residual class
Rule 4(a) classifies devices intended for self-testing as class C, except for a closed list: detection of pregnancy, fertility testing, determining cholesterol level, and detection of glucose, erythrocytes, leucocytes and bacteria in urine, which are class B. This is an exhaustive product list, not a criterion. There is no carve-out in the IVDR for self-tests whose result is preliminary or not critical — a self-test outside those seven items is class C. Rule 4(b) provides that devices for near-patient testing are classified in their own right, which means the near-patient designation does not raise the class; the intended purpose still does.
MDCG 2020-16 rev.4 adds a boundary that affects a growing product category. A testing service offered to lay persons is a self-test where the lay person carries out at least part of the testing procedure, such as adding a reagent or placing the specimen on a cassette. Standalone specimen receptacles and collection kits used only for collection are not self-tests — but if the lay person also performs part of the testing, the whole kit is a self-test.
Rule 5 assigns class A to products for general laboratory use, accessories possessing no critical characteristics, buffer solutions, washing solutions, general culture media and histological stains intended by the manufacturer for in vitro diagnostic procedures relating to a specific examination; to instruments intended specifically for in vitro diagnostic procedures; and to specimen receptacles. The qualifier no critical characteristics does real work — a reagent that can negatively influence the benefit-risk ratio of the whole device is not covered. Rule 6 makes class B residual, and Rule 7 classifies controls without a quantitative or qualitative assigned value as class B. Read Rule 7 against implementing rule 1.6 and the position is clear: a control with an assigned value for a class D assay is itself class D. Defaulting every control to class B is an IVDR classification shortcut that a notified body will unpick.
What the IVDR classification decides about your conformity assessment route
Article 48(10) allows class A devices to be self-declared through the EU declaration of conformity under Article 17 after the Annex II and Annex III technical documentation is drawn up — except that for class A devices placed on the market in sterile condition, the manufacturer applies Annex IX or Annex XI, with notified body involvement limited to establishing, securing and maintaining sterile conditions.
Article 48(9) puts class B through Annex IX Chapters I and III with an assessment of the technical documentation under Section 4 for at least one representative device per category of devices. Article 48(7) puts class C through the same chapters with that assessment for at least one representative device per generic device group — a different and narrower sampling unit. For both, and for class D, self-testing and near-patient testing devices additionally attract the technical documentation assessment in Annex IX Section 5.1, and companion diagnostics require the notified body to consult a national medicines authority or the European Medicines Agency under Annex IX Section 5.2.
Class D is the heaviest route. Article 48(3) requires Annex IX Chapters I, II (except Section 5) and III, with Article 48(4) offering Annex X type-examination coupled with Annex XI as the alternative. Article 48(5) requires the notified body, where an EU reference laboratory has been designated under Article 100, to have that laboratory verify the claimed performance and compliance with common specifications by laboratory testing focused on analytical and diagnostic sensitivity. Article 48(6) requires expert consultation where no common specifications exist and it is the first certification for that type of device. Those laboratories now exist: Commission Implementing Regulation (EU) 2023/2713 designated five for hepatitis and retrovirus, herpesvirus, bacterial infection and respiratory virus markers, with conformity assessment tasks applying from 1 October 2024, and Implementing Regulation (EU) 2025/2526 added parasite infection and blood grouping markers with tasks applying from 1 May 2026.
The legacy dates, and the condition that already expired
Your IVDR classification also decides which legacy deadline you are working to. Article 110, as amended by Regulation (EU) 2024/1860, keeps three dates open. Devices covered by a Directive 98/79/EC certificate, and class D devices that were self-declared under the Directive but now need a notified body, may be placed on the market until 31 December 2027. Class C devices in the same position have until 31 December 2028. Class B devices and class A devices placed on the market in sterile condition have until 31 December 2029. Separately, Regulation (EU) 2023/607 removed the former sell-off deadline from Article 110(4), so devices lawfully placed on the market may continue to be made available without an end date.
The conditions in Article 110(3c) are cumulative, and one of them is already behind us. Point (d) required the manufacturer to have put a quality management system in place in accordance with Article 10(8) no later than 26 May 2025 — a single date applying to every class, not a staggered one. Point (e) required a formal application to a notified body by 26 May 2025 for class D, 26 May 2026 for class C and 26 May 2027 for class B and sterile class A; point (f) required a signed written agreement with that notified body by 26 September 2025, 26 September 2026 and 26 September 2027 respectively. A class B device with a nominally open December 2029 date is outside the derogation entirely if the quality management system was not in place by 26 May 2025.
Two points for manufacturers outside the Union. The formal application under point (e) may be lodged by the authorised representative, which is often the practical route. And under Article 47(2), a classification dispute with a notified body is referred to the competent authority of the manufacturer's Member State — for a manufacturer with no place of business in the Union, that anchors to the representative's Member State, which makes the choice of representative jurisdiction a decision with a consequence attached. Article 11(3)(c) requires the representative to comply with the Article 28 registration obligations and to verify that the manufacturer has complied with Article 26; Article 11(4) leaves classification, technical documentation, performance evaluation and the quality management system with the manufacturer. Over-classifying is not a safe hedge either — an unnecessary class C or D route consumes scarce notified body capacity and can put those transitional dates out of reach. We are not a law firm and do not provide legal advice.
Sources
Regulation (EU) 2017/746, Articles 11, 26, 27, 28, 29, 47, 48, 100 and 110; Annex VIII Sections 1 and 2 (Rules 1 to 7)
Corrigendum to Regulation (EU) 2017/746, OJ L 334, 27 December 2019, p. 167 (Annex VIII Rule 2)
MDCG 2020-16 rev.4 — Guidance on Classification Rules for in vitro Diagnostic Medical Devices under Regulation (EU) 2017/746, March 2025
Regulation (EU) 2024/1860 of 13 June 2024; Regulation (EU) 2023/607 of 15 March 2023; Regulation (EU) 2022/112 of 25 January 2022
Commission Implementing Regulation (EU) 2023/2713 of 5 December 2023 designating EU reference laboratories, as amended by Implementing Regulation (EU) 2025/2526 of 16 December 2025
COM(2024) 43 final of 23 January 2024, explanatory memorandum (notified body involvement under Directive 98/79/EC and under the IVDR)
Who wrote this
Medex is a medical device manufacturer established in Ankara and a registered authorised representative in EUDAMED under SRN TR-AR-000057550. We are not a law firm and do not provide legal advice. Send us your IVD list with the stated intended purpose of each assay, and we will respond in writing.
For IVD manufacturers outside the Union, Medex acts as EU authorised representative and files the Article 28 EUDAMED registrations that follow from the class you assign.
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