Class I is the lowest-risk category under the EU Medical Device Regulation and the only class where the manufacturer can self-declare conformity without a Notified Body certificate for the device itself. That is the headline. The fine print is that Class I is not a free pass. The manufacturer still carries the full Article 10 obligations: a QMS proportionate to the risk class, technical documentation per Annexes II and III, a clinical evaluation, a PMS system, and the EU declaration of conformity drawn up under Annex IV. Three Class I sub-categories — sterile (Is), with measuring function (Im), and reusable surgical instruments (Ir) — still need a Notified Body for those specific aspects. Class I is the lightest path through the MDR. It is not the absence of MDR.

By Tibor Zechmeister and Felix Lenhard. Last updated 10 April 2026.

TL;DR

  • Class I is the lowest of the four MDR risk classes and the only one where the manufacturer self-declares conformity for a standard (non-sterile, non-measuring, non-reusable-surgical) device. The legal basis is Article 52(7) of Regulation (EU) 2017/745, in combination with Annex IV.
  • Classification into Class I is not a choice. It is the output of applying Annex VIII, most often under Rule 1 for non-invasive devices or Rule 13 for other active devices that no higher rule captures. The default answer for non-invasive devices is Class I unless another rule pulls the device higher.
  • Class I still carries the full Article 10 manufacturer obligations, including a QMS under Article 10(9), technical documentation under Annexes II and III, a clinical evaluation under Article 61 and Annex XIV, risk management under Annex I, and PMS under Article 83.
  • The three Class I sub-categories that still require Notified Body involvement are Class I sterile (Is), Class I with a measuring function (Im), and Class I reusable surgical instruments (Ir). The Notified Body assesses only the specific aspect — sterility, metrology, or reprocessing — not the full QMS or the full technical documentation.
  • The most common Class I mistake is the opposite of what founders fear. It is not over-classifying a Class I device as something higher. It is refusing to engage with the MDR at all on the assumption that the device is "obviously" not a medical device, or that Class I means "nothing to do."

A Vienna startup that had the easiest path in the MDR and died anyway

The hardest Class I story we carry is not one about documentation or auditors. It is a bankruptcy.

A Vienna-based startup built a product that was a medical device by the Article 2(1) definition. Nobody at the company wanted to hear that. They had been told early on that what they were building would likely be regulated, and they disagreed. They went to market without MDR compliance. Revenue came in. Traction looked real. Then a competitor sued them. The court ordered them to stop selling until the product was MDR-compliant. Revenue went to zero overnight.

At that point they hired Tibor. Within the first analysis it became clear: the device could have been classified as Class I. Annex VIII pointed directly at the lightest conformity assessment route in the entire Regulation. No Notified Body for the device itself. No clinical investigation. A QMS proportionate to the risk. A technical file. A declaration of conformity. Weeks of work, not years. Tens of thousands of euros, not hundreds of thousands.

But by then the runway was gone. The cash had drained into legal defence and lost revenue. The company ran out of money and went bankrupt. Tibor's assessment, quoted verbatim: "especially bitter because it would have been so easy."

That is the Class I story founders never hear. Class I does not kill companies. The refusal to read the Regulation kills companies. The lightest path through the MDR is only light if you walk it. Ignoring it is the most expensive option in the entire Regulation.

This post exists because the Vienna pattern keeps repeating, and it does not have to.

What Class I actually means

Class I is the lowest of the four MDR risk classes — below Class IIa, Class IIb, and Class III — and it covers devices that pose minimal risk to the patient or user. The class is defined by Article 51 of Regulation (EU) 2017/745 and determined by the classification rules in Annex VIII.

For non-invasive devices, the default rule is Annex VIII Rule 1: "all non-invasive devices are classified as class I, unless one of the rules set out hereinafter applies." That single sentence is the reason most simple, non-invasive, non-active devices end up in Class I. The device is Class I unless another rule pulls it higher. Rule 2 (non-invasive devices for channelling or storing substances), Rule 3 (non-invasive devices for modifying biological or chemical composition), and Rule 4 (non-invasive devices in contact with injured skin or mucous membranes) are the main rules that can escalate a non-invasive device out of Class I. If none of them applies, Rule 1 settles it.

For active devices, Rule 13 of Annex VIII is the residual: all active devices that are not covered by any other rule are Class I. Most simple powered devices that do not diagnose, administer energy, or monitor vital functions live here.

The classic Class I examples include non-sterile elastic bandages, simple manual wheelchairs, wooden tongue depressors, reusable surgical instruments (which fall into the Ir sub-category), examination gloves that are not sterile, stethoscopes, and many basic mobility aids. The full picture is broader, but the pattern is consistent: low risk, low invasiveness, no energy administration, no diagnostic or therapeutic decisions.

Classification into Class I is not a choice. It is the result of applying Annex VIII to the device's intended purpose under Article 2(12). If the rules point to Class I, the device is Class I. If the rules point higher, no amount of wishful thinking moves it back down. The classification walkthrough for any device — Class I or otherwise — is covered in our pillar post on MDR device classification.

The four Class I sub-categories

"Class I" is not one category. Under the MDR it is four, and the difference between them is the difference between a self-declaration and a Notified Body relationship.

Class I (standard). Non-sterile, non-measuring, non-reusable-surgical-instrument Class I devices. The manufacturer self-declares conformity under Article 52(7) of Regulation (EU) 2017/745 and draws up the EU declaration of conformity in accordance with Annex IV. No Notified Body certificate for the device itself. This is the lightest path in the MDR.

Class I sterile (Is). Class I devices placed on the market in a sterile condition. A Notified Body is involved, but only for the aspects of manufacture and validation related to securing and maintaining sterile conditions. The Notified Body does not assess the full QMS or the full technical documentation for these devices — only the sterility-related processes.

Class I with measuring function (Im). Class I devices with a measuring function, where the metrological aspects affect safety or performance. A Notified Body assesses the conformity of the device as regards the metrological requirements — not the full QMS or the full technical documentation.

Class I reusable surgical instruments (Ir). Reusable surgical instruments classified as Class I. A Notified Body is involved for the aspects related to reuse of the device, in particular cleaning, disinfection, sterilisation, maintenance, and functional testing, and the related instructions for use. Again, the scope of Notified Body involvement is narrow — the reprocessing story, not the full file.

The Is/Im/Ir categories sit between standard Class I and Class IIa in terms of Notified Body burden. They are still Class I in the sense that the rest of the conformity assessment follows the Class I logic — but with a Notified Body certificate for the specific aspect that made them Is, Im, or Ir. Founders frequently miss this subtlety and either assume "Class I means no Notified Body ever" or "measuring function means Class IIa." Neither is correct.

What self-certification under Article 52(7) and Annex IV means

Self-certification is the legal mechanism that makes Class I (standard) the lightest MDR path. Article 52(7) of Regulation (EU) 2017/745 provides that manufacturers of Class I devices other than those placed on the market in sterile condition, with a measuring function, or consisting of reusable surgical instruments, shall declare the conformity of their products by issuing the EU declaration of conformity referred to in Article 19 after drawing up the technical documentation set out in Annexes II and III.

Read carefully: the manufacturer declares conformity. The manufacturer draws up the technical documentation. The manufacturer carries the full responsibility. The absence of a Notified Body is not an absence of obligations. It is a reassignment of the conformity assessment responsibility to the manufacturer alone.

The EU declaration of conformity itself is defined by Article 19 and Annex IV. Annex IV lists the minimum content that the declaration must contain: the manufacturer's name and address, the UDI-DI where applicable, the name, trade name, and product reference of the device, the risk class, a statement of conformity with the relevant provisions of the Regulation, references to the harmonised standards applied, references to any common specifications applied, and the date, place, and signature of the person authorised to sign on behalf of the manufacturer. The declaration is a real legal instrument, not a form letter. Signing it commits the manufacturer to the accuracy of everything in the underlying technical file.

The CE mark is affixed after the declaration is drawn up. The technical documentation is held by the manufacturer and must be made available to competent authorities on request. The documentation must be kept for at least ten years after the last device has been placed on the market under Article 10(8), and fifteen years for implantable devices (not relevant for Class I in practice, but worth noting for completeness).

What Class I still requires — the full Article 10 obligations

The biggest Class I misconception is that self-certification means "less work." It means a different allocation of the work. Article 10 of the MDR sets out the general obligations of manufacturers, and the core obligations apply to Class I devices exactly as they apply to Class III devices. The depth and proportion change with risk class. The list of obligations does not.

Quality management system under Article 10(9). The manufacturer must establish, document, implement, maintain, keep up to date, and continually improve a QMS that ensures compliance in the most effective manner and in a manner that is proportionate to the risk class and the type of device. For Class I, a QMS conforming to the relevant parts of EN ISO 13485:2016+A11:2021 is the practical path. The harmonised standard provides presumption of conformity with the QMS obligations where it applies. For standard Class I, the QMS is not audited by a Notified Body — but the competent authority can request evidence of it, and market surveillance increasingly does. The QMS has to exist and has to work.

Technical documentation under Annexes II and III. Annex II sets out the content of the technical documentation for the device itself (device description, information to be supplied, design and manufacturing information, GSPR checklist, risk-benefit analysis, product verification and validation). Annex III sets out the technical documentation on post-market surveillance. Both apply to Class I. The file can be proportionately lighter than a Class IIb file, but every section of Annex II must be addressed for a Class I device.

Clinical evaluation under Article 61 and Annex XIV. Every medical device, including Class I, requires a clinical evaluation. For most Class I devices, the clinical evaluation is based on literature review, clinical data from equivalent devices, and post-market clinical data rather than a new clinical investigation. This is legitimate — Article 61 and Annex XIV explicitly allow it — but "legitimate" is not the same as "skipped." A written clinical evaluation report is required for Class I devices and the clinical evaluation must be updated throughout the product lifecycle.

Risk management under Annex I. The general safety and performance requirements in Annex I apply to all devices regardless of class. Risk management under EN ISO 14971:2019+A11:2021 provides the framework. Class I devices need a risk management file, hazard analysis, risk control measures, and residual risk evaluation, proportionate to the risk profile.

Post-market surveillance under Article 83. Every manufacturer must plan, establish, document, implement, maintain, and update a PMS system proportionate to the risk class. For Class I devices, the PMS system can be lean — a PMS plan, a PMS report updated when necessary, and a process for handling complaints, incidents, and field safety corrective actions. MDCG 2025-10 (December 2025) describes the PMS system in practice. The PMS report replaces the PSUR (Periodic Safety Update Report) for Class I devices — PSURs are required from Class IIa upward.

PRRC under Article 15. A Person Responsible for Regulatory Compliance is required. Micro and small enterprises are not required to have the PRRC within their organisation, but they must have one permanently and continuously at their disposal. For a small Class I startup, external PRRC coverage is a legitimate and common arrangement.

Vigilance under Articles 87–92. Incident and field safety corrective action reporting obligations apply to every manufacturer, Class I included.

Registration and UDI. Class I manufacturers must register themselves and their devices in EUDAMED (to the extent EUDAMED modules are functional) and assign UDIs per the MDR timelines.

None of this is optional because the device is Class I. The depth is proportionate. The obligations are not.

Common Class I mistakes

"It's Class I, so we don't need anything." The single most expensive mistake, and the pattern behind the Vienna bankruptcy. Class I is the lightest path, not the absence of a path. Skipping the path altogether costs more than walking it.

Assuming the device is not a medical device at all. Article 2(1) of Regulation (EU) 2017/745 is the qualification question. If the intended purpose maps to the Article 2(1) definition, the device is a medical device and the MDR applies. Class I is inside the Regulation, not outside it. The qualification question comes before the classification question. For devices that genuinely are not medical devices, the Purpose Pass described in our Subtract to Ship framework post is the right tool.

Confusing Class I with Class Is, Im, or Ir. A device that is sterile, has a measuring function, or is a reusable surgical instrument is still Class I, but with Notified Body involvement for that specific aspect. Founders who plan for standard Class I and then discover their device is Class Im two months before launch lose significant time and money.

Using a template QMS without customising it. The classic Berlin templates failure. A QMS full of placeholder company names, processes the company does not run, and references to standards that do not apply is not a QMS. It is paper. Competent authorities can and do look at Class I QMS during market surveillance.

Skipping the clinical evaluation because "it's only Class I." Not allowed. Article 61 and Annex XIV apply to all classes. The CER can be literature-based, but it has to exist and has to be defensible.

Assuming Class I means the device cannot harm anyone. Low risk is not zero risk. Class I devices can still cause incidents, trigger FSCAs, and appear in vigilance reports. The PMS system has to be ready for that possibility on day one.

Mis-applying Rule 1 for devices that have a measuring function, sterile packaging, or active energy components. Rule 1 is a default, not a universal answer. Walk through all the Annex VIII rules before concluding Class I. Missing Rule 2, 3, or 4 on a non-invasive device — or missing a special rule — is how Class I classifications get overturned at the Notified Body review.

The Subtract to Ship angle on Class I

The Subtract to Ship methodology treats Class I as the clearest win condition in the entire classification landscape. If the device genuinely is Class I, the framework's job is to make sure the startup actually claims that win — and then builds the lightest, defensible file that Annex II, Annex III, Annex IV, and Article 10 require, and nothing more.

Subtraction in a Class I project means cutting every activity that only applies at Class IIa or higher. Full Notified Body QMS audits (not required for standard Class I). Mandatory PSURs (required from Class IIa). Notified Body technical documentation review (not required for standard Class I). Clinical investigations (rarely required for Class I). Every one of these is a common line item in consultants' Class I proposals. Every one of them can usually be cut if the device is actually Class I.

Addition in a Class I project — the thing the Vienna story should embed in every founder's memory — is treating the Class I path as if it does not exist, skipping it, and then paying the price when a competitor, a customer, or a court forces the issue. Adding the Class I path, even minimally, is always cheaper than adding nothing and dealing with the consequences.

The discipline is the same as in every class: trace every activity to a specific MDR article or annex. For Class I, the list is shorter than for Class III. That is the whole point.

Reality Check — Where do you stand on Class I?

  1. Have you applied Article 2(1) to confirm your device is a medical device, before asking what class it is?
  2. Have you walked through the relevant rules of Annex VIII — not just Rule 1 — and confirmed that no higher rule applies?
  3. Is your device standard Class I, or is it Class Is (sterile), Class Im (measuring), or Class Ir (reusable surgical)? Do you know which, and have you planned Notified Body involvement if needed?
  4. Do you have a QMS proportionate to Class I in place, built to reflect your actual operations, and not a template with another company's name in it?
  5. Is your technical documentation organised per Annex II and Annex III, with every section addressed even if briefly?
  6. Do you have a clinical evaluation report compliant with Article 61 and Annex XIV, based on the evidence path (literature, equivalence, or investigation) that matches your device?
  7. Do you have a PMS plan and a PMS report process compliant with Article 83, proportionate to Class I?
  8. Is your EU declaration of conformity drafted in line with Annex IV, with all the required content, ready to sign on the day you place the first device on the market?
  9. Have you assigned a PRRC under Article 15, either in-house or through a documented external arrangement?
  10. If a competent authority walked in next week and asked to see your Class I technical documentation, QMS, clinical evaluation, and PMS records, could you produce them within a reasonable time — and would they survive scrutiny?

Frequently Asked Questions

What is a Class I medical device under the MDR? A Class I medical device is the lowest-risk category under Regulation (EU) 2017/745. The class is determined by the classification rules in Annex VIII, most often by Rule 1 for non-invasive devices or Rule 13 for active devices that no higher rule captures. Class I devices pose minimal risk to patients and users. Examples include non-sterile bandages, simple manual wheelchairs, stethoscopes, and reusable surgical instruments (which fall under the Ir sub-category).

Can I really self-certify a Class I medical device without a Notified Body? For standard Class I devices — non-sterile, without a measuring function, and not reusable surgical instruments — yes. Article 52(7) of the MDR allows the manufacturer to declare conformity by drawing up the technical documentation set out in Annexes II and III and issuing an EU declaration of conformity in line with Annex IV. No Notified Body certificate is required for the device itself. For Class Is, Im, and Ir sub-categories, a Notified Body is still involved for the specific aspect (sterility, metrology, or reprocessing) that triggered the sub-category.

What does Class I still require from the manufacturer? All the core Article 10 manufacturer obligations: a QMS proportionate to the risk class under Article 10(9), technical documentation under Annexes II and III, a clinical evaluation under Article 61 and Annex XIV, risk management under Annex I and EN ISO 14971:2019+A11:2021, post-market surveillance under Article 83, vigilance reporting under Articles 87–92, a PRRC under Article 15, EUDAMED registration and UDI assignment to the extent applicable, and the EU declaration of conformity under Annex IV. Class I is the lightest path, not an exemption.

Does a Class I device need a QMS? Yes. Article 10(9) requires every manufacturer to have a QMS proportionate to the risk class and type of device. For Class I, the QMS is not audited by a Notified Body for standard Class I, but it must exist, must work, and must be available to competent authorities on request. Compliance with EN ISO 13485:2016+A11:2021 provides presumption of conformity with the QMS obligations where the standard applies.

Is a clinical evaluation required for Class I? Yes. Article 61 of the MDR applies to all classes. For most Class I devices, the clinical evaluation can be based on a literature review and equivalence considerations rather than a new clinical investigation, and the clinical evaluation report can be proportionately lighter than for higher classes. But a written clinical evaluation is required and must be kept up to date throughout the device lifecycle.

What is the difference between Class I, Class Is, Class Im, and Class Ir? Class I (standard) is the self-certified lowest-risk category with no Notified Body involvement. Class Is is Class I placed on the market in a sterile condition — Notified Body involvement is limited to the sterility-related aspects. Class Im is Class I with a measuring function — Notified Body involvement is limited to the metrological aspects. Class Ir is reusable surgical instruments classified as Class I — Notified Body involvement is limited to the reprocessing aspects (cleaning, disinfection, sterilisation, maintenance, functional testing, and related IFU). In all three sub-categories, the Notified Body scope is narrow and does not extend to the full QMS or the full technical documentation.

How long does Class I conformity assessment take? Class I (standard) is typically the fastest MDR path. The time is driven mostly by the manufacturer's readiness: stable intended purpose, complete technical documentation, working QMS, clinical evaluation, PMS plan, and declaration of conformity. With a focused startup and a sparring partner who knows the MDR, a well-scoped Class I project can move from stable intended purpose to declaration of conformity in a matter of months rather than years. Class Is, Im, and Ir add the time required for the Notified Body to assess the specific aspect that triggered the sub-category.

Is Class I the cheapest MDR path? For standard Class I, yes. It avoids Notified Body fees for the device itself, which are the single largest recurring cost in the higher classes. The cheapest MDR path is not free, however — the Class I file still requires real effort on the QMS, technical documentation, clinical evaluation, and PMS. The most expensive Class I "path" in practice is the one the Vienna startup chose: ignoring the MDR entirely, losing revenue to an injunction, and running out of money before the file could be built.

Sources

  1. Regulation (EU) 2017/745 of the European Parliament and of the Council of 5 April 2017 on medical devices, Article 2(1) (definition of medical device), Article 10 (general obligations of manufacturers, including Article 10(8) on technical documentation retention and Article 10(9) on QMS), Article 19 (EU declaration of conformity), Article 51 (classification), Article 52(7) (conformity assessment for Class I), Article 61 (clinical evaluation), Article 83 (post-market surveillance system), Annex I (general safety and performance requirements), Annex II (technical documentation), Annex III (technical documentation on post-market surveillance), Annex IV (EU declaration of conformity), Annex VIII (classification rules, including Rule 1 and Rule 13), Annex XIV (clinical evaluation and post-market clinical follow-up). Official Journal L 117, 5.5.2017.
  2. MDCG 2021-24 — Guidance on classification of medical devices, October 2021.
  3. EN ISO 13485:2016 + A11:2021 — Medical devices — Quality management systems — Requirements for regulatory purposes.

This post is part of the Device Classification & Conformity Assessment series in the Subtract to Ship: MDR blog. Authored by Felix Lenhard and Tibor Zechmeister. The Vienna bankruptcy is a real pattern we have watched repeat. The Class I path is the lightest in the Regulation, but only if the founder walks it — the most expensive option in the entire MDR is refusing to engage with it at all. If your device might be Class I and the complexity of your specific situation exceeds what a blog post can cover — and for most startups, it will, because every device is different — a classification and conformity-assessment working session with a sparring partner who has done this across fifty-plus certifications is usually the fastest path to a defensible file.