Findings
An accessory is defined as a finished device that supports, supplements, or augments the performance of a parent device.
Accessories are classified based on their individual risk profiles when used with parent devices, which may differ from the classification of the parent device.
The De Novo process can be used for new accessory types with no existing classification, enabling lower-risk accessories to be classified in Class I or II.
Articles not specifically intended for use with a medical device (e.g., generic batteries or monitors) are not considered accessories unless labeled or promoted for such use.
FDA encourages using pre-submission requests to obtain feedback before submitting Accessory Requests or De Novo classifications.

Recommendations
Determine whether an article qualifies as an accessory by evaluating its intended use with a parent device based on labeling and promotional materials.
Evaluate the risks associated with the accessory when used as intended with its parent device, considering both unique and parent-related risks.
Use the Accessory Request process for new or existing accessories to propose appropriate classifications, supported by evidence of risk profiles and proposed regulatory controls.
Submit De Novo requests for new accessory types lacking existing classifications, providing data on performance, risks, and mitigation measures.
Include clear and comprehensive labeling for accessories, specifying compatibility and performance with identified parent devices.

Regulatory Considerations
Classification of accessories should reflect their risks and required controls, independent of their parent device classification.
Accessories categorized as Software as a Medical Device (SaMD) must meet the same risk-based classification framework applied to other medical devices.
Manufacturers can request reclassification or exemption from 510(k) requirements for previously classified accessories through applicable FDA mechanisms.
FDA must respond to Accessory Requests for existing accessory types within 85 days and De Novo requests within 120 days, as specified in the FD&C Act.
The Paperwork Reduction Act governs the submission of accessory classification requests, requiring compliance with established timelines and documentation requirements.