Updated for the IVDR amendment proposal (2025)

In the fast-evolving world of diagnostic testing, many laboratories rely on in-house developed tests to meet specific patient needs. These tests, known as In-House IVDs (IH-IVDs) — sometimes also referred to as laboratory-developed tests (LDTs) — are essential for specialised applications, niche diagnostics, or situations where tailored solutions are required, and commercial solutions not available.

The creation and use of these in-house IVD devices is clearly regulated in Article 5.5 of the In Vitro Diagnostic Regulation (IVDR). This article describes the requirements and conditions that healthcare facilities must meet if they want to manufacture and use in-house IVDs. The requirements are further detailed in guidance MDCG 2023-1.

In terms of its interpretation, the IVDR thus regulates individual devices and their safety and performance requirements.

However, in the laboratory world, the first thing that comes to mind is diagnostic methods. Such a method, or diagnostic examination, is typically a sequence, a workflow of activities that are performed automatically or manually according to specifications in order to obtain a specific result. Within this workflow, various elements are used, such as infrastructure, components such as instruments or reagents, or other auxiliary materials.

In most cases, several such components are used sequentially or in parallel. If this combination is not intended by the original manufacturers, the laboratory, by definition, creates an in-house device – in this case, a system combining several components. The situation is similar if one or more components are not approved for IVD purposes, for example, Research Use Only (RUO).
In this case, the laboratory thus creates a Laboratory Developed Test (LDT – the method), which is based on one (or more) in-house IVD devices.

Many laboratories ensure the quality of their methods by applying appropriate quality management standards. The classic example is compliance or accreditation according to ISO 15189. By applying and adhering to this standard, laboratories ensure appropriate competence in the laboratory, suitable processes and documentation, and the establishment of state-of-the-art methods.
However, the legal requirement of the IVDR for in-house devices applies at the device level.

Still, a common misconception persists because many believe that if a laboratory is ISO 15189 accredited, it automatically meets all regulatory requirements for IH-IVDs. However, this is not the case.

Understanding the Difference: IH-IVDs vs Examination Procedures

ISO 15189 focuses on the quality and competence of the laboratory. It ensures that processes — from specimen handling to analytical procedures — are performed correctly, consistently, and safely. In practical terms, ISO 15189 governs the examination procedure: workflows, staff competence, equipment use, and quality management within the laboratory.

IH-IVDs, however, are devices in their own right under EU law, specifically regulated under IVDR Article 5(5).

What an IH-IVD can be:

• Developed entirely in-house from raw materials or components
• A re-purpose of RUO materials for diagnostic use
• A combination of CE-IVDs used in a new way
• A CE-IVD used outside the manufacturer’s instructions

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From a regulatory perspective, an IH-IVD is not the same as an examination procedure. While ISO 15189 covers laboratory operations, it does not automatically address device safety, performance, or conformity with IVDR requirements.

Protocols, patient samples, and workflow descriptions fall under ISO 15189. The IH-IVD device itself — whether software, reagents, or hardware — must meet IVDR safety and performance expectations.

Why ISO 15189 Alone Is Not Sufficient for IH-IVDs

ISO 15189 provides an excellent foundation for laboratory competence and quality management. With the latest IVDR amendment proposal, ISO 15189–accredited laboratories would be implicitly recognised as lower-risk actors operating under robust quality controls.

However, ISO 15189 accreditation does not, on its own, fulfil all IVDR obligations for in-house devices.

IH-IVDs introduce device-specific responsibilities, including:

• Technical documentation covering design, development, and intended use
• appropriate quality management system going beyond ISO 15189 and considering relevant individual activities (e.g. design control according to ISO 13485)
• Performance evaluation demonstrating analytical and, where applicable, clinical performance
• Risk management addressing device-specific hazards and mitigation measures (typically aligned with ISO 14971 or ISO 22367)
• Regulatory justification based on patient safety, clinical need, or public health interest

In short:

• ISO 15189 governs how the laboratory operates
• IVDR governs whether the device itself is safe and performs as intended

IVDR clarifies that ISO 15189 is a regulatory anchor, not merely a starting point — but it is not a replacement for device compliance.

Bridging the Gap: Using ISO 15189 as an Enabler

Despite its limits, ISO 15189 is a powerful enabler for IVDR compliance when used intentionally.

Laboratories can leverage their existing QMS to:

• Map workflow controls to device development requirements
• Integrate risk management into existing quality structures
• Reuse documentation practices to support IVDR technical files
• Align verification and validation activities with device performance evaluation
• Use complaint handling, CAPA, and clinical use experience reviews to support post-market obligations
• The implementation of IH-IVD requirements can be further reinforced by applying ISO5649.

With careful planning, laboratories do not need two separate systems. A single integrated approach can address both ISO 15189 and IVDR requirements, filling gaps where laboratory accreditation alone does not suffice.

Key Takeaways

• ISO 15189 ≠ IVDR compliance: accreditation ensures competent laboratory procedures, not device conformity
• IH-IVDs are devices: they fall under IVDR and require performance evidence, risk management, and documentation
• ISO 15189 is key for IH-IVD: Not only is it mandatory (art. 5.5 c), but the ideal framework to manage and integrate IH-IVDs into daily work
• An integrated QMS works best: extend ISO 15189 processes rather than duplicating them
• Early alignment matters: proactive compliance prevents gaps as enforcement matures

For laboratories navigating the in-house device landscape, understanding where ISO 15189 stops — and IVDR begins — is essential. ISO 15189 defines how work is done. IVDR ensures that the devices behind those procedures are safe, effective, and compliant.

*We have compiled the above information to the best of our knowledge, yet our blog entries do not constitute expert advice and cannot substitute your own examination of the legal situation applicable to you and your institution.