IVDR classification rules 1–7

Regulatory basis

IVDR 2017/746, Annex VIII. Seven rules classify IVDs based on the risk posed by the diagnostic information they generate, the severity of conditions they detect, and the vulnerability of the populations they serve.

Disclaimer

This site provides general information only and does not constitute legal or regulatory advice. Always consult the official regulation text and a qualified regulatory professional.

The IVDR classification logic

Unlike MDR's 22 rules — which focus heavily on physical device characteristics — IVDR classification focuses on what information the test provides and what happens if it is wrong. The key factors are:

Severity of the condition being diagnosed or monitored
Risk of transmission (for infectious disease tests)
Vulnerability of the intended population (self-test users, blood donors, etc.)
Impact on individual clinical decisions vs. population-level screening
Whether the device is a companion diagnostic

As with MDR, where more than one rule applies, the highest resulting class prevails.

Rule 1 — Class D (highest risk)

Class D IVDs are those whose failure could cause life-threatening harm directly, or could allow life-threatening conditions to go undetected in circumstances where timely detection is critical.

Rule 1 classifies as Class D any IVD intended to be used for:

Detection or confirmation of the presence of, or exposure to, an agent of a transmissible spongiform encephalopathy (TSE) such as CJD
Detection or confirmation of the presence of, or exposure to, HIV-1, HIV-2, HTLV-I, HTLV-II (confirmation / supplemental assay)
Nucleic acid amplification testing (NAT) for HIV, HBV, HCV, HTLV, when used in blood, blood component, cell, tissue, or organ donation screening
Detection of hepatitis B, hepatitis C, HTLV where used as a primary screen in donation settings
Blood grouping (ABO system, Rh system, Kell, Duffy, Kidd) and other red cell antigen and antibody testing used prior to transfusion or for compatibility testing

Why Class D for blood group typing?

A transfusion of incompatible blood can be rapidly fatal. ABO/Rh errors in donor or patient testing carry catastrophic consequences. The EU reference laboratory review requirement for Class D provides an additional verification layer for these critical assays.

Rule 2 — Class C (medium-to-high risk)

Class C covers IVDs where errors could lead to dangerous clinical decisions for individual patients, though not necessarily with the immediate life-threatening consequences of Class D.

Rule 2 classifies as Class C IVDs intended for:

Detection of sexually transmitted infections (e.g. syphilis, chlamydia, gonorrhoea, HSV)
Detection of infectious agents such as rubella, toxoplasma, CMV, EBV — particularly relevant in pregnancy
Testing for oncology markers directly influencing treatment decisions (e.g. PSA, CEA, CA-125, HER2 status)
HLA typing (human leukocyte antigen) for histocompatibility in transplantation
Companion diagnostics — IVDs that identify patients eligible for a specific targeted therapy
Testing to determine nutritional or metabolic status with clinical significance (e.g. folate, vitamin B12 in clinical contexts)
Blood glucose monitoring devices (including self-monitoring blood glucose / SMBG)
HbA1c assays
Troponin and other cardiac biomarkers
Near-patient coagulation (e.g. INR / PT for anticoagulation monitoring)
Screening tests for infectious disease not covered by Rule 1
Genetic testing used to predict disease predisposition or hereditary conditions
Prenatal screening tests for genetic conditions
Self-test versions of any Class D IVD (a self-test format of a Class D analyte is Class C, not D)

Rule 3 — Class B (low-to-medium risk)

Class B covers IVDs that support clinical decisions, but where the consequences of errors — while clinically significant — are unlikely to cause life-threatening harm in most circumstances.

Rule 3 classifies as Class B IVDs that are not covered by Rules 1, 2, 4, 5, 6, or 7, and which provide information that is clinically meaningful.

Most routine diagnostic tests fall here:

Routine haematology (FBC, differential, coagulation screening for non-near-patient use)
Routine clinical chemistry (liver function, kidney function, thyroid function, lipid panels)
General serology not covered by Class C or D
Urinalysis (dipstick, microscopy)
Allergy testing panels (general IgE)
Tumour markers used for monitoring (not diagnosis of therapy-linked targets)
Drug of abuse testing in clinical (not forensic) settings
Most microbiology culture media and identification systems

Rule 4 — Class A (lowest risk)

Class A covers IVDs where errors are unlikely to directly affect clinical decision-making about individual patients — typically because the output is not a direct patient result, or is so far upstream in the testing process that multiple other checks exist.

Rule 4 classifies as Class A any IVD that is:

Intended only for quality control purposes without a specific quantitative or qualitative claim related to patient diagnosis
A general laboratory instrument or equipment (not specifically an IVD by itself)
A specimen receptacle (blood collection tubes, urine cups, swabs — unless they contain additives that specifically affect the analyte)
A buffer, diluent, or wash solution of a general nature
A general histological stain not specific to a diagnostic target
A calibrator or control material for use with Class A devices only

Rule 5 — Instruments: assigned to Class A

Instruments — hardware components of IVD systems — that are not specific to any particular analyte and are used for general IVD purposes are Class A unless the instrument is specifically designed and used exclusively with a Class B, C, or D assay, in which case it takes the class of the highest-class assay it is intended to be used with.

Rule 6 — Self-tests

Self-tests are IVDs intended to be used by laypersons, without the interpretation of a healthcare professional. The classification of a self-test is:

If the analyte would be Class D when used professionally → Class C as a self-test
If the analyte would be Class C → remains Class C as a self-test
If the analyte would be Class B → elevated to Class C as a self-test (due to increased risk of user error and misinterpretation)
If the analyte would be Class A → Class B as a self-test

This upward reclassification reflects the greater inherent risk when tests are performed by lay users without professional oversight.

Self-test examples: home pregnancy tests (Class C), home glucose monitors (Class C), OTC HIV tests (Class C as self-test, vs Class D for blood bank screening).

Rule 7 — Near-patient testing

Near-patient testing (NPT) — also called point-of-care testing (POCT) — is IVD testing performed outside a traditional laboratory, typically at or near the site of patient care. Under Rule 7:

Near-patient tests are classified according to the same rules as laboratory tests for that analyte
There is no automatic upward reclassification for near-patient format alone

However, near-patient tests may still be Class C (e.g. bedside troponin, near-patient INR) based on the analyte under Rule 2.

Applying the rules: worked examples

Device	Applicable rule	Class
Blood collection tube (EDTA)	Rule 4	A
Clinical chemistry analyser (multi-parameter)	Rule 5	A (instrument) / B (assay)
Urine dipstick (general urinalysis)	Rule 3	B
CRP point-of-care test at clinical threshold	Rule 2	C
Blood glucose self-monitoring kit	Rules 2 + 6	C
Home HIV screening test (self-test)	Rules 1 + 6	C (self-test version of D analyte)
HIV confirmation (Western blot)	Rule 1	D
ABO blood group typing reagent	Rule 1	D
BRCA companion diagnostic	Rule 2	C
NAT HIV blood screening	Rule 1	D

Official references

Reference	Description
IVDR Annex VIII	Classification rules 1–7 (full text)
IVDR Art. 47	Classification procedure
IVDR Art. 5(5)	Self-test and near-patient testing definitions
IVDR Art. 100	EU reference laboratories
MDCG 2020-16	Companion diagnostics guidance

The IVDR classification logic​

Rule 1 — Class D (highest risk)​

Why Class D for blood group typing?​

Rule 2 — Class C (medium-to-high risk)​

Rule 3 — Class B (low-to-medium risk)​

Rule 4 — Class A (lowest risk)​

Rule 5 — Instruments: assigned to Class A​

Rule 6 — Self-tests​

Rule 7 — Near-patient testing​

Applying the rules: worked examples​

Related pages​

Official references​