Post-Market Monitoring (PMM) is the mandatory, proactive system that providers of high-risk AI systems must establish and maintain under the EU AI Act to continuously collect and analyze performance and incident data after a system has been placed on the market or put into service.

Recognizing that an AI system's real-world performance cannot be fully validated in a pre-market lab environment, PMM closes the compliance loop. It is a planned, documented process that treats deployment not as an endpoint, but as the start of a critical observation phase. The objective is to ensure the system continues to operate as intended within its approved scope and to detect any emerging risks—such as performance degradation (model drift), unforeseen misuse, or changes in context—that could compromise safety or fundamental rights. This data directly feeds back into the risk management system, triggering necessary corrective or preventive actions.

An effective Post-Market Monitoring plan must be systematic and encompass:

Performance Surveillance: Continuously tracking key accuracy, robustness, and cybersecurity metrics against predefined baselines to identify deviations or degradation over time.

Incident Data Collection: Implementing channels to gather information on any malfunction, dip in performance, or user-reported issue, including near-misses that did not cause harm.

Feedback Loop Integration: Establishing processes to systematically analyze collected data, investigate root causes, and determine if updates, retraining, corrective actions, or, in severe cases, recalls are necessary.

Periodic Update Reporting: Compiling the findings of the PMM activities into a periodic update report for the relevant authorities, as required by the EU AI Act, documenting the system's ongoing conformity.

Regulatory Context: Article 61 of the EU AI Act explicitly mandates a post-market monitoring system for providers of high-risk AI systems. This requirement is integrated with the Act's broader risk management obligations (Article 9), ensuring compliance is a dynamic, lifecycle commitment rather than a static, pre-market event.

Strategic Value: Proactive PMM is a strategic asset, not just a compliance cost. It enables providers to maintain system reliability, protect their brand reputation by addressing issues before they cause widespread harm, and gather invaluable real-world data to improve future product versions. Failure to maintain an adequate PMM system can lead to non-compliance findings, even for a system that was initially certified, resulting in enforcement actions and market withdrawal.