DE: Beratung Zulassung und Zertifizierung von Medizinprodukten EN: Consulting and Certification Medical Device

Risk Classification of Medical Devices

What does the risk classification of medical devices mean and why is it so important?

The risk classification of medical devices is one of the key steps in the approval process in Europe under Regulation (EU) 2017/745 (MDR) and describes the classification of a medical device according to the potential risk to patients and users. This classification significantly determines the regulatory effort involved, from technical documentation and clinical evaluations to market launch. The higher the risk, the stricter the requirements for evidence, testing, and monitoring.

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The risk classification of medical devices is one of the key steps in the approval process in Europe under Regulation (EU) 2017/745 (MDR) and describes the classification of a medical device according to the potential risk to patients and users. This classification significantly determines the regulatory effort involved, from technical documentation and clinical evaluations to market launch. The FDA cites risk management as the most frequently cited finding under the new QMSR.

Is my product a medical device?

The decisive factor is the intended use specified by the manufacturer: A product falls under the MDR only if it serves a medical purpose as defined in Article 2 of the MDR (e.g., diagnosis, prevention, monitoring, treatment, or alleviation of diseases). Products without a medical intended use may instead be classified as, for example, cosmetics, biocides, or general consumer products.

You can find details of the definitions on our page “Differences of Pharmaceuticals and Medical Devices“.

What are the risk classes for medical devices according to MDR?

The MDR regulates that products are assessed based on their intended use, duration of use, location of contact in the body, and invasiveness. The deeper a product is inserted into the body and the longer it remains in the body, the higher the risk. The higher the risk, the more intensive the requirements, especially with regard to the involvement of a Notified Body, Clinical Data, Conformity Assessment, and Post-Market Surveillance.

The four risk classes of the MDR

Medical devices according to the MDR are classified into four main classes:

Class I, IIa, IIb, and Class III

Class I has three subcategories:
Is (sterile), Im (measuring), and Ir (reusable surgical instruments)

In-Vitro Diagnostics (IVD)

In vitro diagnostic medical devices are covered by IVDR (EU) 2017/746, which provides for its own classification system:

Classes A, B, C, and D

US Approval System (FDA)

In the US, medical devices are approved by the Food and Drug Administration (FDA) on the basis of three risk classes:

Class I, Class II, and Class III

What is the difference between the classes?

Classes I, IIa, IIb, III: The difference lies in the potential risk and, consequently, in the complexity of the authorization process.

Before applying the regulations, the MDR assigns each product to a basic product group. This classification determines which rules from Annex VIII apply. Three characteristics are decisive here; however, they are not mutually exclusive but can occur in combination.

Active devices rely on an energy source not generated by the human body or gravity and convert this energy.
Rules 9 through 13 apply to these devices.
Examples: infusion pumps, ventilators, surgical lasers.

Non-active devices function without their own energy source, relying solely on their physical properties.
Rules 1 through 4 apply to non-invasive versions.
Examples: bandages, non-powered catheters, surgical instruments. 

Invasive devices penetrate the body either fully or partially. The classification is determined by how the product is introduced (through a body orifice or surgically), how long it remains in place, and where it acts; in particular, contact with the central circulatory system or central nervous system significantly increases the class. Rules 5 through 8 apply to invasive products.

The same medical function may fall into a different risk class depending on the product group.

ClassRisk PotentialApplicationApproval
Class ILow Riskmostly non-invasive (e.g., dressings, wheelchairs)

Typically self-certification without a Notified Body

Class IIaModerate Riskoften short-term use (e.g., hearing aids, many software products)Notified Body required
Class IIbIncreased Risklong-term contact or active devices (e.g., infusion pumps)Notified Body required
Class IIIHigh Risklife-saving or implantable products (e.g., heart valves, implants)highest requirements, including clinical data

Do I need a Notified Body, or is self-certification acceptable?

Only Class I products (excluding special cases) may be self-certified.

As soon as a product falls under Class Is, Im, Ir, IIa, IIb, or III, a Notified Body must be involved. Colloquially, the Notified Body is often referred to as “TÜV”; in fact, TÜV organizations (e.g., TÜV SÜD, TÜV Rheinland) are some of the well-known Notified Bodies, but they are not the only ones.

Similarly, the terms “approval” or “authorization” in everyday language usually refer to conformity assessment .

How does the IVDR classification differ from the MDR classification?

For in vitro diagnostic medical devices (IVDs), the IVDR (EU) 2017/746 applies. It provides for its own classification system with classes A, B, C, and D.

Unlike the rule-based, product-specific classification of the MDR (Annex VIII), the IVDR uses seven classification rules (Annex VIII IVDR) that focus more on the risk to individuals and public health.

Class A represents the lowest risk (e.g., laboratory aids), while Class D represents the highest (e.g., tests for life-threatening, communicable pathogens in blood donations). Here, too (except for a subset of Class A devices), a Notified Body must be involved.

Software or Apps as a Medical Device (SaMD)

Software can also be a Medical Device. Internationally, this is referred to as SaMD (Software as a Medical Device). Once again, the intended purpose is decisive: An app that merely logs data (e.g., a simple step counter log) is usually not a medical device. An app that makes diagnoses, calculates treatment decisions, or medically interprets measured values, on the other hand, is.

Rule 11 of Annex VIII of the MDR is central to the classification of software. In practice, this often results in a classification of at least Class IIa, and in cases involving decisions that could lead to a serious deterioration in health or surgical interventions, it may also result in Class IIb or III. Software that controls or influences another medical device is classified in the same class as that device. In addition, the internationally harmonized IMDRF Framework for SaMD categorization aids in the reasoning process.

Accessories for Medical Devices

Accessories are items that are not medical devices in themselves but are intended by the manufacturer to enable or support the use of a medical device when used together with it. Accessories are classified independently, meaning they are not automatically placed in the same class as the main product. It undergoes its own risk assessment according to the rules in Annex VIII.

How is the risk class of a medical device determined?

In the EU, classification is carried out in accordance with the classification rules in Annex VIII of the MDR. Annex VIII contains 22 rules that provide a structured decision-making process for each product. The rules can be divided into four groups: non-invasive devices, invasive devices, active devices, and special rules (including those for substances, nanomaterials, and software).

The specific conformity assessment procedure that applies is then determined by the identified class and the corresponding annexes.

Duration of Use

Place of Application

Reusable Surgical Instrument

Active Medical Device

Use of Biological Material

< 60

Minutes

< 30 Days

> 30 Days

Degree of
Invasivity

Central Circulatory System / Nervous System

therapeuticdiagnosticHumanAnimal

There is no blanket assignment of medical devices to a fixed risk class; the assignment applies to a specific, individual product.

If problems arise with the classification, the applicant, after reviewing all available literature on differentiation or classification, may first contact the relevant state authority or a Notified Body and, finally, submit an application for classification and/or differentiation pursuant to Section 6(2) of the Medical Devices Act (MPDG) to the Federal Institute for Drugs and Medical Devices (BfArM).

What is the significance of the risk class and intended use in the approval process?

The intended purpose of a medical device determines its intended use and is therefore directly linked to its risk class. The risk class is highly significant and has a major impact on the manufacturer’s activities, as almost all processes are tailored to it.

The risk class affects the requirements for:

 
The intended purpose of a medical device determines its intended use and is therefore directly linked to its risk class. The risk class is highly significant and has a major impact on the manufacturer&apos;s activities, as almost all processes are tailored to it.

Intended Purpose as a Core Regulatory Criterion

The intended purpose has an often underestimated but central role in the entire MDR process.
Specifically, the intended purpose regulates:

  • the legal categorisation of the product (e.g. cosmetic, biocide, medicinal product, medical device)
  • the requirements for clinical performance, compatibility and scope of clinical evidence, and thus forms the basis for the “benefit-risk assessment”
  • the placement on the market of the product and its commissioning
  • the normal conditions of use
  • the scope of the general safety and performance requirements and the design, and manufacturing requirements
  • the instructions for use, the summary of safety and clinical performance, and the technical documentation (product description and specification)

EU MDR vs. FDA Classification

The classification of medical devices in the European Union (EU) and the United States (US) is different not only in terms of terminology, but also in terms of the overall regulatory approach. While the EU follows a rule-based classification system, the US relies on a product- and risk-based comparative assessment.

In the EU risk classification according to the MDR regulations (Annex VIII) is based on criteria such as invasiveness, duration of use and intended purpose. A structured decision path is provided for each product. The assessment and approval are mainly carried out by Notified Bodies.

In the US classification is based on risk and what is known as substantial equivalence, which refers to the similarity to already approved products (predicate devices). The FDA is directly responsible for testing and approval via procedures such as 510(k) or PMA (premarket approval).

 EU MDRUSA FDA
Risk ClassClass I, IIa, IIb, IIIClass I, II, III
ClassificationBasis Rile-based acording to Annex VIIIRisk- and comparison-based (510(k), PMA)
Responsible AuthorityNotified Body (except Class I)FDA directly

How can WQS help with classification?

Accurate risk classification is essential for achieving fast, cost-efficient and safe approval.
WQS competently guides you through this entire process:

  • Analysis and definition of your intended purpose
  • Identification of the correct risk class according to MDR
  • Preparation of technical documentation and classification justification
  • Support in communication with notified bodies
  • Advice on software, accessories, and IVD classification

Need more information?

WQS provides you with detailed information on your subject.
You can also explore our FAQ page and other resources for further insight
– or simply contact us for direct support.

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FAQ´s

Frequently Asked Questions

According to the EU MDR, medical devices are classified into four risk classes: Class I, IIa, IIb and III. This classification is based on the risk posed by the product when used as intended. The higher the class, the stricter the regulatory requirements for approval, clinical evaluation and market surveillance.

The class is determined using the 22 rules in Annex VIII of the MDR, based on intended use, invasiveness, duration of use, active nature, and, where applicable, biological material:

  • Class I: low risk, non-invasive (e.g., dressings) with the subclasses: Is (sterile), Im (with measuring function), and Ir (reusable surgical instruments).
  • Class IIa: medium risk, short-term use (e.g., hearing aids)
  • Class IIb: increased risk, long-term contact or active products (e.g., infusion pumps)
  • Class III: high risk, life-saving or implantable products (e.g., implants, heart valves)

As the class increases, so do the requirements for clinical data, technical documentation, and the involvement of a Notified Body.

The decisive factor is the medical intended purpose as defined in Article 2 of the MDR (e.g., diagnosis, treatment, monitoring, or alleviation). If the primary effect is pharmacological, immunological, or metabolic, the product is more likely to be a medicinal product. For borderline cases, WQS offers consultation to help determine the classification.

The risk classification of medical devices in the EU is based on the classification rules in Annex VIII of the MDR.
Specific criteria for classification are:

  • Determination of the intended purpose
  • Duration of use
  • Place of use
  • Reusable surgical instrument
  • Active medical device
  • Use of biological material

In the EU, classification is rule-based according to Annex VIII of the MDR (Class I, IIa, IIb, and III) and relies on Notified Bodies.
In the US, the FDA classifies products into Class I, II, and III based on risk and equivalence to existing products for device approval (510(k) or PMA).

The intended purpose is the foundation of the medical device risk classification. According to the MDR and IVDR, it defines the intended medical benefit, the intended use, the intended patient groups and the intended application. This directly determines the risk class (I, IIa, IIb, III) and the required conformity assessment.

In vitro diagnostic devices (IVDs) are regulated under EU IVDR 2017/746 and classified into four risk-based categories according to their intended purpose and the associated risks to patients and public health:

  • Class A – low risk
  • Class B – moderate risk
  • Class C – high individual risk or moderate public risk
  • Class D – high public health risk

Yes, if the software has a medical intended purpose, such as making diagnoses or calculating treatment decisions. Rule 11 of Annex VIII of the MDR is central to the classification, which often results in a classification of at least Class IIa. Apps that are purely for logging or documentation without medical interpretation are generally not medical devices.

Class I products (excluding special cases Is/Im/Ir) may be self-certified. For Class Is/Im/Ir as well as Classes IIa, IIb, and III, a Notified Body must be involved. The organizations commonly referred to as “TÜV” are some, but not the only, Notified Bodies.

Classifying a product in a lower class than it should be can result in a product that is not marketable, recalls, regulatory actions, and liability risks. Classifying a product in a higher class than it should be causes unnecessary effort and costs.
If you’re unsure, WQS can help you determine the correct risk class for your medical device.

Class I medical devices are generally subject to self-certification by the manufacturer. Key requirements include the preparation of technical documentation, a risk management system, a quality management system (QMS), a self-conducted conformity assessment (without a Notified Body), UDI marking, and an EU Declaration of Conformity.

Further Links

  • European Parliament & Council of the EU: Regulation (EU) 2017/745 on Medical Devices (MDR), May 5, 2017 – eur-lex.europa.eu
  • European Parliament & Council of the EU: Regulation (EU) 2017/746 on In-Vitro Diagnostic Medical Devices (IVDR), May 5, 2017 – eur-lex.europa.eu

Support for US companies to enter the European market. EU Rep, Certification, QM System, Technical Documentation, support of the Procedure, selection of a Notified Body, support of the Certification Procedure, preparation of a Clinical Evaluation, support of Clinical Studies, including the Logistical Concepts.

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136 4th Street north, Suite 201
St Petersburg, Florida 33701

Telefon: (925) 212-7683
Email: werner@us.wqs.de
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This page provides regulatory information and does not constitute legal advice. Regulatory requirements vary by jurisdiction.
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