MDR classification rules 1–22
Regulatory basis
MDR 2017/745, Annex VIII. All 22 classification rules must be applied systematically. Where more than one rule applies, the highest resulting class prevails.
Disclaimer
This site provides general information only and does not constitute legal or regulatory advice. Classification of specific products requires careful analysis of the intended purpose and all applicable rules.
How to apply the rules
Where multiple rules apply, the highest resulting class takes precedence. The manufacturer must document the complete classification rationale in the technical documentation, including which rules were considered, why lower-class rules were not applicable, and the reasoning for selection of the highest applicable rule.
Rules 1–4 — Non-invasive devices
Non-invasive devices are those that do not penetrate the body surface (including body orifices).
| Rule | Class | Key condition |
|---|---|---|
| Rule 1 | I | All non-invasive devices unless another rule applies |
| Rule 2 | IIa | Non-invasive devices intended to channel or store blood, body liquids, cells, tissues, or gases for transfusion/infusion/administration into the body (unless connected to an active device Class IIb or III, in which case: IIb or III) |
| Rule 3 | IIa | Non-invasive devices that modify the biological or chemical composition of human tissue, cells, blood, or other body liquids, or of other liquids intended for implantation — where the treatment involves filtration, centrifugation, or gas/heat exchange |
| Rule 4 | IIa / IIb | Non-invasive devices that come into contact with injured skin or mucous membranes: IIa if for mechanical barrier, compression, or absorption of exudates; IIb if managing the micro-environment of a wound; Class III if for chronic wounds or wounds healing by secondary intent |
Rules 5–8 — Invasive devices
| Rule | Class | Key condition |
|---|---|---|
| Rule 5 | I | Invasive devices intended to contact only intact skin (e.g. examination gloves) |
| Rule 6 | IIa | Transient-use surgically invasive devices; IIb if for use specifically in direct contact with the heart, central circulatory system, or CNS; Class III if they are absorbable or if they are used with medicinal products in an integral manner |
| Rule 7 | IIa | Short-term surgically invasive devices; IIb if for use in direct contact with heart/CNS/central circulatory system; Class III if they are absorbable, or for use with medicinal products |
| Rule 8 | IIb | Long-term implantable devices and surgically invasive devices intended for long-term use; Class III if for implantation in teeth, spine, or in direct contact with heart/central circulatory system/CNS; Class III for breast implants, penile implants, and total joint replacements |
Rules 9–13 — Active devices
Active devices depend on an energy source other than gravity or human body energy.
| Rule | Class | Key condition |
|---|---|---|
| Rule 9 | I / IIa / IIb | Active therapeutic devices: Class I if intended to administer/exchange energy in a non-potentially dangerous way; IIa if intended to administer energy to or exchange energy with the patient in a potentially dangerous way (considering the nature, density, and site); IIb if intended to control, monitor, or directly influence performance of Class IIb active therapeutic devices |
| Rule 10 | IIa | Active devices for diagnosis: intended to supply energy absorbed by the human body (except lighting); imaging devices using ionising radiation → IIb |
| Rule 11 | I / IIa / IIb / III | Software: see Software & SaMD classification for full treatment under Rule 11 |
| Rule 12 | I | Active devices intended to administer medicinal products, body liquids, or other substances to or from the body — where done in a potentially dangerous manner → IIb |
| Rule 13 | IIb / III | All other active devices: IIb by default; Class III if intended to diagnose, monitor, or correct a deficiency in the heart/central circulatory system/CNS by delivering energy directly |
Rules 14–22 — Special rules
These rules apply to specific product categories regardless of other rules, and override lower classifications where applicable.
| Rule | Class | Covers |
|---|---|---|
| Rule 14 | III | Devices incorporating, as an integral part, a substance which, if used separately, would be considered a medicinal product (including human blood derivatives) and which is liable to act on the human body with action ancillary to the device |
| Rule 15 | III | Devices used for contraception or prevention of sexually transmitted disease — IIb if implantable or long-term invasive |
| Rule 16 | III | Devices specifically intended for recording diagnostic images generated by X-ray radiation |
| Rule 17 | III | Devices manufactured using tissues or cells of human origin or their derivatives that are non-viable or rendered non-viable (unless they contact only intact skin) |
| Rule 18 | III | Devices manufactured using tissues or cells of animal origin or their derivatives that are non-viable (unless they contact only intact skin) |
| Rule 19 | IIb / III | Devices incorporating or consisting of nanomaterials: IIb if nano presents low-to-medium potential for internal exposure; III if medium-to-high potential |
| Rule 20 | IIb / III | Invasive devices with respect to body orifices — not surgically invasive — intended to administer medicinal products: IIb if inhaled; III if absorbed by the GI tract, nasal/oral mucosa |
| Rule 21 | III | Devices intended to be used for extracorporeal circulation of blood or other liquids through the device, for subsequent reinfusion or infusion |
| Rule 22 | IIb | Devices incorporating a CMR (carcinogenic, mutagenic, or reprotoxic) substance or substances that are endocrine disruptors and may enter the body in substantial quantities |
Common classification traps
| Scenario | Common mistake | Correct approach |
|---|---|---|
| Catheter used temporarily | Classified as Class I non-invasive | Rule 6 applies — surgically invasive device, transient use → IIa |
| Software for diagnosis | Ignored Rule 11 | Must apply Rule 11 and consider severity of condition and reversibility |
| Sterile wound dressing | Self-declared Class I | If sterile: Class Is — NB involvement required for sterility aspects |
| Combination device with drug | Classified as drug only | If device action is principal → Class III under Rule 14 |
| Reusable surgical forceps | Class I self-declared | Class Ir — NB must assess reprocessing aspects |
Related pages
- How classification works
- Class I · IIa · IIb · III
- Software & SaMD classification
- Borderline & combination products
- Devices incorporating a medicinal substance
Official references
| Reference | Description |
|---|---|
| MDR Annex VIII | Full text of all 22 classification rules |
| MDR Art. 51(2) | Commission power to reclassify |
| MDCG 2021-24 | Software classification (Rule 11) |
| MDCG 2019-11 | Qualification and classification of software |
| MDCG 2022-5 | Borderline and classification manual |