---
title: Clinical Evaluation Timelines for Startups: Realistic Planning from Day One
description: Clinical evaluation under MDR takes longer than founders plan. Here are realistic timelines from CEP to CER and the things that break them.
authors: Tibor Zechmeister, Felix Lenhard
category: Clinical Evaluation & Investigations
primary_keyword: clinical evaluation timelines startups
canonical_url: https://zechmeister-solutions.com/en/blog/clinical-evaluation-timelines-startups
source: zechmeister-solutions.com
license: All rights reserved. Content may be cited with attribution and a link to the canonical URL.
---

# Clinical Evaluation Timelines for Startups: Realistic Planning from Day One

*By Tibor Zechmeister (EU MDR Expert, Notified Body Lead Auditor) and Felix Lenhard.*

> **Clinical evaluation under MDR is not a sprint at the end of development. It is a lifecycle process that starts at intended-purpose definition and never ends. For a startup building a non-implantable, non-Class III device, a credible clinical evaluation plan (CEP) to first signed-off clinical evaluation report (CER) typically takes nine to eighteen months of elapsed time, running in parallel with product development. Literature review alone takes six to twelve weeks for a well-scoped question and six months when the scope is wrong. Appraisal and analysis take another six to ten weeks. CER drafting is four to eight weeks for a first complete version. Notified Body review of the CER as part of the technical documentation adds three to nine months on top. The numbers stretch fast when intended purpose shifts, when equivalence claims collapse, or when a pre-market clinical investigation under MDR Article 61(4) becomes unavoidable.**

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

---

## TL;DR

- A realistic CEP-to-first-CER timeline for a non-implantable, non-Class III startup device is nine to eighteen months of elapsed time, running in parallel with product development — not sequentially after it.
- The clinical evaluation plan (CEP) is the gate that determines everything downstream. Rushing the CEP to save two weeks regularly costs four months later when the scope has to be rewritten.
- Literature review is six to twelve weeks when the research question is well-defined, and six months when it is not. The difference is the CEP, not the tooling.
- Appraisal and analysis of the collected data takes another six to ten weeks for a well-scoped evaluation. Novel claims, weak data quality, or unclear benefit-risk arguments push it longer.
- CER drafting is four to eight weeks for a first complete version. Review rounds with the Notified Body add three to nine months of calendar time to the end of the process.
- For implantable and Class III devices, a pre-market clinical investigation under MDR Article 61(4) and Annex XV adds twelve to thirty-six months — often longer than the rest of the project combined.
- The things that break clinical evaluation timelines are not technical. They are intended-purpose drift, equivalence claims that collapse under MDCG 2020-5 scrutiny, and PMCF plans written as an afterthought.

---

## Why clinical evaluation timelines matter more than founders think

Founders plan the product. They plan the QMS. They plan the Notified Body application. The clinical evaluation gets a line item near the end of the Gantt chart, usually labelled "CER — 2 months" and usually sitting right before submission.

That line item is wrong by a factor of five. Clinical evaluation is not a document that gets written at the end. It is a process defined by MDR Article 61 and Annex XIV Part A that starts on the day the intended purpose is first written down and continues past CE marking through Annex XIV Part B post-market clinical follow-up. Treating it as a late-stage deliverable is the single most common planning failure we see, and it is the reason so many startups discover in month eighteen that their submission is blocked by a clinical evaluation they thought was almost done.

This post breaks the process into its five real phases, gives honest ranges for each, names the things that break the timelines, and gives honest class-by-class numbers for what to actually plan with.

## The CEP phase: the gate that determines everything downstream

The clinical evaluation plan (CEP) is required by MDR Annex XIV Part A and defines the scope of the entire evaluation. Intended purpose (referencing Article 2(12)), target population and indications, clinical benefits and performance claims to be substantiated, relevant general safety and performance requirements that need clinical evidence, data sources to be used, appraisal methodology, analysis methodology, acceptance criteria.

Realistic elapsed time for a first CEP on a first device: four to eight weeks. Three weeks is possible when the intended purpose is tightly defined, the team has prior MDR experience, and the relevant GSPRs are clearly identifiable. Twelve weeks is common when the intended purpose is still fluid, the clinical claims are still being negotiated internally, or the team has never written a CEP before.

The CEP is where every downstream hour is won or lost. A vague intended purpose multiplies the literature review effort. A CEP that tries to cover every possible future indication produces a CER that has to substantiate every one of them. A CEP that does not pre-specify appraisal criteria forces a rework round after the Notified Body reads the first CER. The cheapest four weeks in the entire clinical evaluation process are the four weeks spent getting the CEP right before any data is collected.

## The literature review phase: six weeks or six months

Annex XIV Part A requires a critical evaluation of the relevant scientific literature on the device, on devices of the same generic group, on the underlying technology, on the clinical condition, and on the established methods the device relies on. The literature review is structured, pre-specified in the CEP, and reproducible.

For a well-scoped research question with a clear PICO (population, intervention, comparator, outcome) structure inherited from the CEP, a literature review takes six to twelve weeks of elapsed time: two to three weeks for search design and execution across PubMed, Embase, and Cochrane; two to four weeks for title/abstract screening; two to four weeks for full-text screening and data extraction.

When the CEP is weak, the same review takes six months and usually has to be redone. The failure mode is not the tool. It is the question. A vague intended purpose produces an unbounded search, an unbounded search produces thousands of hits, thousands of hits produce a screening bottleneck, and the team ends up re-scoping the search three times before anything useful emerges.

Literature review on an established-methods device — the Graz pattern described in [post 111](/blog/what-is-clinical-evaluation-under-mdr) — can carry most of the clinical evidence burden at a fraction of the cost of a clinical investigation. That is where the Evidence Pass produces its largest savings, and it is the phase where a good CEP earns its keep several times over.

## The appraisal and analysis phase: where the clinical story gets built

Once the literature is collected, the appraisal and analysis phase turns raw data into a clinical argument. Each included source is appraised against the pre-specified criteria in the CEP — methodological quality, relevance to the device and intended purpose, contribution to the clinical question. The appraised data is then analysed against the acceptance criteria for each relevant GSPR.

Realistic elapsed time: six to ten weeks for a well-scoped evaluation with clean literature and clear equivalence arguments. Twelve to sixteen weeks when equivalence under MDCG 2020-5 (April 2020) has to be justified dimension by dimension, or when the clinical benefit argument has to be built from indirect evidence.

This is also the phase where weak data becomes visible. A literature review that looked comprehensive in week eight reveals, during appraisal, that most of the included studies do not actually address the specific claim being made. The fix is not more time in appraisal. The fix is going back to the CEP, narrowing the claim, and repeating the literature review with a tighter question. Most of the calendar damage in clinical evaluation projects happens here, and almost all of it traces back to a CEP that was not tight enough.

## The CER drafting phase: four to eight weeks for a first version

The clinical evaluation report (CER) documents the process, the data, the appraisal, the analysis, and the conclusions about safety, performance, and clinical benefits. It must reference the CEP, demonstrate that the evaluation was conducted according to the pre-specified plan, and map the conclusions onto the relevant general safety and performance requirements in Annex I.

Realistic elapsed time for a first complete CER draft, once appraisal and analysis are done: four to eight weeks. The range depends on the complexity of the device, the number of GSPRs that need clinical evidence, and the quality of the CEP the CER is traceable to. A CER written against a strong CEP mostly writes itself, because the structure, the appraisal criteria, and the acceptance criteria are already fixed. A CER written against a weak CEP is a writing project that keeps discovering problems in the underlying analysis.

Internal review adds another two to four weeks. Peer review by an independent clinical reviewer — required for higher-risk devices and strongly recommended for all startups even when not strictly required — adds another two to three weeks.

## The Notified Body review phase: three to nine months of calendar time

Once the CER is part of the technical documentation submitted to the Notified Body, it enters the review queue. The Notified Body reviews the clinical evaluation as part of the conformity assessment, typically with a clinical expert as part of the review team. Findings come back as questions, non-conformities, or requests for additional evidence.

Realistic elapsed time for the CER portion of Notified Body review, measured from submission to clean close-out: three to nine months. The low end assumes a well-prepared CER, a competent first response to the first set of findings, and a device that fits within the Notified Body's scope and experience. The high end assumes at least one round of significant rework and one or two additional exchanges on specific points.

This is calendar time, not work time. Most of it is queue time on the Notified Body side, not drafting time on the startup side. Which means it cannot be compressed by hiring more people. It can only be compressed by reducing the number of review rounds, which comes back — again — to the quality of the CEP and the discipline of the analysis.

## What breaks clinical evaluation timelines

Five things break these timelines, in rough order of frequency.

**Intended purpose drift.** The intended purpose changes during product development. Every change cascades into the CEP, the literature review, the appraisal criteria, and the CER. A change in month twelve that would have been a one-line edit in month two is now a three-month rework. See [post 41](/blog/intended-purpose-mdr) and [post 42](/blog/intended-purpose-drift) on why intended purpose is the single most leveraged decision in the entire MDR project.

**Equivalence claims that collapse under MDCG 2020-5.** The team plans to claim equivalence to a competitor device, starts the CER assuming the claim will hold, and then discovers — during appraisal or, worse, during Notified Body review — that "sufficient levels of access" to the equivalent device's data is not actually available. MDCG 2023-7 (December 2023) clarifies what "sufficient levels of access" means in practice, and the bar is high.

**PMCF plans written as an afterthought.** Annex XIV Part B requires a PMCF plan before CE marking. Teams that treat PMCF as a post-market problem discover, during Notified Body review, that the PMCF plan has to be rewritten and re-approved before the certificate can be issued.

**Underestimated review cycles.** Teams plan for one Notified Body review round and get three. The right plan assumes two full cycles and treats one as a gift.

**Clinical investigations added late.** The team plans a literature-only evaluation and discovers in appraisal that a specific claim cannot be supported without primary data. A clinical investigation under EN ISO 14155:2020+A11:2024 and MDR Articles 62-82 cannot be set up in a month. Adding one late is the fastest way to add a year to the project.

## Honest ranges by class

These are elapsed-time ranges from a serious start on the CEP to the first clean, Notified-Body-accepted CER. They assume the clinical evaluation runs in parallel with product development, not after it. They assume one full rework cycle with the Notified Body.

**Class I (self-declared, no NB involvement in the CER).** Nine to fifteen months. The CER still has to meet MDR Article 61 and Annex XIV Part A, but there is no Notified Body review on the CER itself. Market surveillance still looks at it.

**Class IIa non-implantable.** Twelve to eighteen months from CEP to clean first CER. Notified Body review of the technical documentation, including the CER, typically adds three to six months of calendar time at the end.

**Class IIb non-implantable.** Fifteen to twenty-four months from CEP to clean first CER. Notified Body review adds four to nine months.

**Class IIb implantable or Class III, with MDCG 2023-7 exemption.** Eighteen to thirty months. The exemption removes the pre-market clinical investigation but not the scrutiny. Equivalence claims get dissected.

**Class IIb implantable or Class III, no exemption.** Thirty to sixty months. A pre-market clinical investigation under Article 61(4), Articles 62-82, Annex XV and EN ISO 14155:2020+A11:2024 becomes the critical path. The investigation itself — protocol, ethics, competent authority, sites, recruitment, follow-up, data lock, analysis — typically runs twelve to thirty-six months on its own.

Match these against the Notified Body and conformity assessment timelines in [post 712](/blog/no-bullshit-medtech-startup-timelines) and [post 725](/blog/mdr-timeline-honest-numbers). The clinical evaluation is usually either the critical path or a close second.

## Common planning mistakes

Five mistakes we see on almost every startup we meet.

**Planning the CER as a two-month task at the end of development.** The CER is the output of a nine-to-eighteen-month process, not a two-month document.

**Skipping the CEP.** Teams write the CER directly from whatever data they have collected, then get told to produce a CEP retrospectively. Retrospective CEPs rarely survive Notified Body scrutiny because the appraisal criteria look reverse-engineered.

**Treating PMCF as a post-market problem.** The PMCF plan must be in the technical file before CE marking. It is part of the clinical evaluation, not a separate deliverable.

**Planning equivalence without testing the claim early.** The equivalence claim should be stress-tested against MDCG 2020-5 in month one, not month fifteen.

**Ignoring the link to risk management under EN ISO 14971:2019+A11:2021.** Clinical evaluation feeds the risk file, and the risk file feeds the clinical evaluation. Teams that treat them as separate workstreams end up reconciling them under deadline pressure.

## The Subtract to Ship angle

The Subtract to Ship framework ([post 65](/blog/subtract-to-ship-framework-mdr)) maps onto clinical evaluation timelines in one specific way. The Evidence Pass, applied honestly at the CEP stage, is what turns an eighteen-month clinical evaluation into a twelve-month one — and what turns a thirty-six-month Class III pathway into a twenty-four-month one when an MDCG 2023-7 exemption is available.

The pass runs in cost order. Intended purpose first: tight, honest, narrow. Literature first among data sources. Equivalence second, only where the access conditions genuinely hold. Clinical investigation last, only for the specific claims literature and equivalence cannot cover. Every hour spent in the CEP phase getting this order right saves four to six hours in later phases.

This is not a trick for going faster. It is a discipline for not going slower than necessary. The timelines above are what happens when the Evidence Pass is applied. Without it, add fifty percent to every range.

## Reality Check — Where do you stand?

1. Is your clinical evaluation plan (CEP) written and approved internally before any literature has been collected, or is the CEP still being drafted alongside the data?
2. Can you state the intended purpose of your device in one sentence that is identical in the CEP, the IFU, the label, and the sales materials?
3. Have you tested your equivalence claim against MDCG 2020-5 dimension by dimension (technical, biological, clinical) and confirmed you have sufficient levels of access under MDCG 2023-7?
4. Is your literature review scoped by a pre-specified research question in the CEP, or are the search terms still being negotiated week by week?
5. Have you allocated at least nine months of elapsed calendar time from CEP start to first clean CER draft, in parallel with product development?
6. Does your plan assume one full Notified Body rework cycle on the CER, or does it optimistically assume a clean first review?
7. Is your PMCF plan drafted now, before CE marking, with methods that are actually feasible within your resources?
8. Is your clinical evaluation traceable end-to-end to your risk file under EN ISO 14971:2019+A11:2021, or are the two files maintained separately?
9. If your device is implantable or Class III and no MDCG 2023-7 exemption applies, have you started clinical investigation planning under EN ISO 14155:2020+A11:2024 early enough that it will not become the critical path of the whole project?
10. When your schedule slips, does the clinical evaluation get the time it needs, or is it the first line item to be compressed?

## Frequently Asked Questions

**How long does a clinical evaluation report actually take to write under MDR?**
For a non-implantable, non-Class III startup device, the first clean CER typically takes nine to eighteen months of elapsed time from CEP start, running in parallel with product development. The CER drafting itself is four to eight weeks, but the work that produces it — CEP, literature review, appraisal, analysis — is the bulk of the time.

**Can a startup compress the clinical evaluation timeline by hiring more people?**
Partially. More people can speed up literature screening and CER drafting, but they cannot speed up Notified Body review queue time or compress the sequential logic of CEP then literature then appraisal then analysis then CER. The biggest compressions come from a tight CEP, not from added headcount.

**How long does Notified Body review of the clinical evaluation take?**
Three to nine months of calendar time for the CER portion of the technical documentation review, typically including one round of findings and responses. This is queue time, not work time, and cannot be compressed by the startup.

**Does the clinical evaluation have to be finished before the Notified Body application?**
The CER must be part of the technical documentation submitted with the conformity assessment application. It does not have to be "finished" in the sense of complete forever — clinical evaluation is a lifecycle process — but it must be a complete, credible, signed-off version of the evaluation at the point of submission under MDR Article 61 and Annex XIV Part A.

**How much extra time does a pre-market clinical investigation add for Class III devices?**
Twelve to thirty-six months on top of the rest of the clinical evaluation timeline. The investigation itself runs under EN ISO 14155:2020+A11:2024 and MDR Articles 62-82 and Annex XV, and it is typically the critical path of the entire MDR project for novel Class III devices where no MDCG 2023-7 exemption applies.

**When should the PMCF plan be written?**
Before CE marking. The PMCF plan is part of the technical documentation and is reviewed by the Notified Body along with the rest of the clinical evaluation under Annex XIV Part B. Teams that write the PMCF plan after CE marking discover that it blocks the certificate.

**What is the single biggest timeline mistake startups make in clinical evaluation?**
Treating the CER as a two-month task at the end of development. The CER is the output of a nine-to-eighteen-month process, and starting it late is the most common reason clinical evaluation becomes the critical path of the whole MDR project.

## Related reading

- [Intended Purpose Under MDR](/blog/intended-purpose-mdr) — the definition in Article 2(12) and why it drives every clinical evaluation decision.
- [Intended Purpose Drift](/blog/intended-purpose-drift) — how scope creep in the intended purpose multiplies the clinical evidence burden.
- [What Is Clinical Evaluation Under MDR?](/blog/what-is-clinical-evaluation-under-mdr) — the pillar post for the clinical evaluation cluster and the starting point if you are new to Article 61 and Annex XIV.
- [MDR Article 61 Clinical Evidence Requirements for Startups](/blog/mdr-article-61-clinical-evidence-requirements-startups) — the paragraph-by-paragraph walkthrough of Article 61.
- [Clinical Evaluation Plan (CEP) Structure](/blog/clinical-evaluation-plan-cep-structure) — the CEP template and what Annex XIV Part A requires in each section.
- [Literature Review for Clinical Evaluation](/blog/literature-review-clinical-evaluation-mdr) — how to scope, run, and document the literature review phase.
- [Equivalence Under MDR](/blog/equivalence-under-mdr) — the dedicated deep-dive on MDCG 2020-5 and "sufficient levels of access."
- [Post 150: Clinical Evaluation Budget Planning](/blog/clinical-evaluation-budget-planning-startups) — the money side of what this post describes on the time side.
- [No-Bullshit MedTech Startup Timelines](/blog/no-bullshit-medtech-startup-timelines) — the overall startup timeline framing that clinical evaluation fits inside.
- [MDR Timeline: Honest Numbers](/blog/mdr-timeline-honest-numbers) — phase-by-phase calendar ranges for the full MDR project.
- [The Subtract to Ship Framework for MDR Compliance](/blog/subtract-to-ship-framework-mdr) — the methodology pillar, including the Evidence Pass referenced in this post.

## Sources

1. Regulation (EU) 2017/745 of the European Parliament and of the Council of 5 April 2017 on medical devices, Article 61 (clinical evaluation), Annex XIV Part A (clinical evaluation), Annex XIV Part B (post-market clinical follow-up). Official Journal L 117, 5.5.2017.
2. MDCG 2020-5 — Clinical Evaluation — Equivalence: A guide for manufacturers and notified bodies, April 2020.
3. MDCG 2023-7 — Guidance on exemptions from the requirement to perform clinical investigations pursuant to Article 61(4)-(6) MDR and on 'sufficient levels of access' to data needed to justify claims of equivalence, December 2023.
4. EN ISO 14155:2020 + A11:2024 — Clinical investigation of medical devices for human subjects — Good clinical practice.
5. EN ISO 14971:2019 + A11:2021 — Medical devices — Application of risk management to medical devices.

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*This post sits in the Clinical Evaluation & Clinical Investigations cluster of the Subtract to Ship: MDR blog. Authored by Tibor Zechmeister and Felix Lenhard. Clinical evaluation is where the distance between the plan on the slide and the plan the Notified Body will accept is measured in months of runway — and where the discipline of writing a tight CEP in week two is worth more than any tool, template, or headcount you can add in month fifteen.*

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*This post is part of the [Clinical Evaluation & Investigations](https://zechmeister-solutions.com/en/blog/category/clinical-evaluation) cluster in the [Subtract to Ship: MDR Blog](https://zechmeister-solutions.com/en/blog). For EU MDR certification consulting, see [zechmeister-solutions.com](https://zechmeister-solutions.com).*