The U.S. Food and Drug Administration (FDA) has officially opened a comment period on a citizen petition that could fundamentally change how radiology artificial intelligence (AI) is regulated. The petition, submitted by Rubrum Advising on behalf of Harrison.ai, proposes a streamlined regulatory pathway designed to reduce the burden of existing requirements for established vendors.
Under the proposed model, manufacturers who have already secured 510(k) clearances for their software would be allowed to comply with postmarket study requirements instead of submitting entirely new 510(k) applications when adding new capabilities. This alternative would exist alongside the traditional 510(k) pathway, which would remain available to all vendors.
Addressing the Innovation Gap
The petition highlights a significant “innovation gap” between the United States and Europe. Currently, manufacturers often limit the features of the products they offer in the U.S. market, seeking clearance for a narrow range of imaging modalities or specific diagnostic tasks. According to the petition, the U.S. regulatory process is often viewed as burdensome and ill suited to the rapid pace of AI evolution compared with European standards.
Data presented to the FDA suggests that AI coverage of diagnostic tasks in the U.S. is currently only about 1 percent. In contrast, the same AI products often provide full diagnostic coverage in the United Kingdom, European Union, and Asia.
Scope of the Proposed Exemption
The petition seeks to exempt four specific generic device types from traditional premarket notification under certain conditions:
- Radiological computer-assisted diagnostic (CADx) software for lesions suspicious of cancer.
- Medical image analyzers.
- Radiological computer-aided triage (CADt) and notification software.
- Radiological computer-assisted detection and diagnosis (CADe/x) software.
To qualify for this streamlined pathway, manufacturers would need to meet strict criteria. For CADt devices, a vendor must already possess at least one clearance under that specific classification. For CADx, medical image analyzers, or CADe/x devices, a manufacturer must have at least one prior clearance under any of those three specific regulations. The petition notes that this is appropriate because the special controls for these devices are largely aligned with one another.
Safety and Postmarket Oversight
Safety remains a central focus of the proposal. Even under this streamlined pathway, manufacturers would be required to implement a robust postmarket plan, maintain transparency, and provide necessary training measures.
All existing regulatory requirements regarding quality systems, establishment registration, device listing, and special controls would remain in force. The petition authors point out that the FDA has the express statutory authority to issue postmarket surveillance as a special control and has exercised similar partial exemption authority in the past.
The ultimate goal of the proposal is to foster a “try-first” culture for AI in American industry while maintaining the safety standards the FDA requires. Electronic or written comments on this petition must be submitted to the FDA by February 27, 2026.