Background to the Revision
NMPA Announcement No. 58 revises the 2021 AI medical device classification guidance following two years of review feedback from manufacturers, academic institutions, and provincial drug administrations. The revision is driven by the rapid evolution of AI model architectures — particularly large language model-based clinical decision support tools — that were not contemplated in the original 2021 framework.
New Sub-Category Structure
The revised guidance introduces three AI device sub-categories: AI Decision Support Software (Class II, advisory only, no autonomous therapeutic recommendation), AI Diagnostic Software (Class II or III depending on clinical significance of output), and AI Autonomous Intervention Software (Class III, including AI-controlled drug delivery and radiotherapy planning systems). Each sub-category has distinct technical documentation requirements.
Boundary Clarification — Class II vs Class III AI Diagnostics
The most significant change is the classification boundary for AI diagnostic software. Under the 2021 guidance, classification depended primarily on whether the software output was "advisory" or "conclusive". The revised guidance replaces this binary with a clinical-risk matrix incorporating factors including disease severity, reversibility of harm, availability of clinical override mechanisms, and intended user qualification level.
Transition Arrangements
Manufacturers holding existing NMPA registration certificates for AI medical devices have 18 months from the announcement date to assess whether their products fall under a different sub-category under the revised framework and, if so, to submit a voluntary reclassification application. NMPA has confirmed that reclassification applications will not require a full re-evaluation of previously accepted clinical evidence.