Common Specifications (CS) are legally binding sets of technical or clinical requirements adopted by the European Commission under Article 9 of EU MDR 2017/745 and IVDR 2017/746. They apply where harmonized standards are absent, insufficient, or where public health concerns exist, and grant a presumption of conformity when followed.
What is Common Specifications (CS)?
Common Specifications (CS) are a regulatory instrument defined in Article 2 of both the EU Medical Device Regulation (MDR 2017/745) and the In Vitro Diagnostic Regulation (IVDR 2017/746). The text describes a CS as a set of technical or clinical requirements, other than a standard, that provides a means of complying with the legal obligations that apply to a device, process, or system.
CS sits alongside harmonized standards as a route to demonstrating conformity, but they come from a different source. Harmonized standards are developed by European standards bodies such as CEN and CENELEC. A CS is adopted directly by the European Commission through an implementing act, after consulting the Medical Device Coordination Group (MDCG). Under the earlier In Vitro Diagnostic Directive (98/79/EC), the equivalent concept was called a Common Technical Specification (CTS).
Why Common Specifications (CS) matter in medical device development
For most requirements, a manufacturer can choose which standards to apply. A CS narrows that freedom. Article 9 states that manufacturers must comply with an applicable CS unless they can justify a solution that delivers at least an equivalent level of safety and performance. That justification is hard to build in practice, so a published CS behaves as a near-mandatory requirement.
Getting this wrong carries real cost. A Notified Body reviews CS compliance during conformity assessment and technical documentation review, and it must check applicable CS even when the manufacturer does not cite them. A gap can stall CE marking, trigger nonconformities, and delay market access. Applied CS also has to appear in the Declaration of Conformity, the technical documentation, and, where relevant, the Summary of Safety and Clinical Performance (SSCP) and the Post-Market Clinical Follow-up (PMCF) plan.
How Common Specifications (CS) work
A CS is created and applied through a defined sequence:
- Trigger. The Commission identifies a gap: no harmonized standard exists, an existing one is insufficient, or a public health concern needs addressing.
- Consultation. The Commission consults the MDCG and relevant stakeholders, taking account of existing European and international standards.
- Adoption. The CS is adopted as a Commission Implementing Regulation and published in the Official Journal of the European Union, which gives it legal force.
- Application. Manufacturers map the CS to the relevant General Safety and Performance Requirements (GSPR) in Annex I and build the evidence into their technical file.
- Assessment. The Notified Body verifies conformity with the CS during audit and technical documentation review.
CS can cover the GSPR, technical documentation, clinical evaluation, post-market clinical follow-up, and clinical investigation requirements. A concrete example is Commission Implementing Regulation (EU) 2022/2346, which lays down CS for the Annex XVI products without an intended medical purpose, such as dermal fillers, equipment for liposuction, high-intensity light and laser equipment for hair or skin treatment, and brain stimulation equipment. That regulation has applied since 22 June 2023.
Common challenges and best practices
Teams often treat CS as optional guidance. They are not. Because they can carry the same legal weight as a regulation, a missed CS is a compliance gap, not a stylistic choice.
Common pitfalls and how to handle them:
- Missing an applicable CS. Search EUR-Lex for Commission Implementing Regulations linked to MDR 2017/745 or IVDR 2017/746 early in the project, and re-check before each submission.
- Weak equivalence arguments. If you deviate from a CS, document an evidence-backed rationale showing at least equivalent safety and performance. Assume a Notified Body will challenge it.
- Forgetting downstream references. Cite applied CS in the Declaration of Conformity, technical documentation, and clinical or performance evaluation, not just in test reports.
- QMS impact. A CS can reach into quality management system processes, so update procedures where the CS demands it.
IVDR manufacturers should pay particular attention. The IVD field has fewer harmonized standards, so CS carries more of the compliance burden there than in the medical device space.
How SJML helps with Common Specifications (CS)
SJML delivers EU MDR and IVDR compliance as a service, which includes identifying and applying Common Specifications within a device technical file. Regulatory teams support device classification, CE marking strategy, and technical documentation, and they align the quality management system to ISO 13485 and the requirements a CS introduces. Where a manufacturer needs to justify an alternative solution, SJML helps structure the safety and performance rationale that a Notified Body will scrutinize. Regulatory sustenance services keep technical files current as new CS are published.
Frequently asked questions
Yes, in effect. Article 9 of EU MDR and IVDR requires manufacturers to comply with an applicable CS unless they can justify a solution that achieves at least an equivalent level of safety and performance. For Annex XVI products without a medical purpose, compliance with the relevant CS is required outright. A published CS therefore functions as a binding requirement.
Both grant a presumption of conformity, but they differ in source and force. Harmonized standards are voluntary and developed by CEN and CENELEC. A CS is adopted by the European Commission as an implementing regulation and is effectively mandatory. CS are used where no suitable harmonized standard exists, an existing one is insufficient, or a public health concern must be addressed.
Published CS appear in the Official Journal of the European Union and are searchable on EUR-Lex. Look for Commission Implementing Regulations that reference Regulation (EU) 2017/745 for medical devices or Regulation (EU) 2017/746 for IVDs. Examples include Regulation (EU) 2022/2346 for Annex XVI products. Check for updates before each submission, since new CS are issued over time.
Yes. Article 9 of IVDR 2017/746 mirrors the MDR provision and lets the Commission adopt CS for in vitro diagnostic medical devices. Because the IVD sector has relatively few harmonized standards, CS often carries more of the conformity burden than in the medical device field. The predecessor concept under the old IVD Directive was the Common Technical Specification (CTS).
Related terms
- Harmonized Standards
- General Safety and Performance Requirements (GSPR)
- Notified Body
- EU MDR 2017/745
- Declaration of Conformity
