Regulatory Services
When a device's regulatory classification is uncertain — because the intended use is novel, the technology crosses device categories, or the line between device, drug, and combination product is unclear — a 513(g) request asks FDA to provide a formal determination. It is the most reliable way to resolve classification uncertainty before investing in a development program or submission.
Clarify Your Device ClassificationClassification Strategy
Section 513(g) of the FD&C Act allows any person to request that FDA classify a device or provide information regarding the regulatory requirements applicable to a device. A 513(g) request is appropriate when: the device's classification cannot be confidently determined through existing classification regulations and product codes, the device incorporates elements of multiple device categories whose combined classification is unclear, the device's intended use creates uncertainty about whether it is a device, drug, combination product, or IVD, or the company needs a formal FDA determination to support regulatory strategy decisions or investor due diligence.
A 513(g) request is not always the best first step. In many cases, a pre-submission (Q-Sub) meeting request is more appropriate — particularly when the company also has questions about the submission pathway, required data, and other regulatory requirements that a 513(g) request alone won't address. We assess whether a 513(g) request, a Q-Sub, or a combination of both is the right approach for the device's specific classification question before recommending a path forward.
A 513(g) request must include a description of the device, its intended use, and the specific questions for which FDA's determination is sought. The quality of the questions determines the utility of FDA's response. Vague questions produce general answers that may not resolve the actual uncertainty. Specific, narrowly drawn questions about the device's regulatory status, classification, and applicable requirements produce specific answers that can be relied upon in making development and business decisions.
The device description in a 513(g) request must be comprehensive enough for FDA to make an informed classification determination — including the device's mechanism of action, the materials involved, the intended use population, the indications for use, and how the device interacts with the body. For novel technologies, we include comparison to existing classified devices to help FDA identify the closest classified analog and the classification rationale that would apply.
FDA's response to a 513(g) request provides the company's classification determination, the applicable regulatory class, the pre-market submission pathway (510(k), De Novo, or PMA), and often the applicable device-specific guidance documents. This information is the foundation of the regulatory strategy — it defines the submission type, the review standard, the performance testing that will be required, and the timeline from development to market authorization. We analyze 513(g) responses in the context of the company's development stage and resources to develop a realistic, resource-appropriate regulatory strategy.
When FDA receives a 513(g) request, it reviews the device description, intended use, proposed indications, and mechanism of action against the existing classification regulations in 21 CFR Parts 862–892 and its product code database. FDA identifies the most analogous classified device type, assigns the regulatory class and product code, and specifies the pre-market submission pathway — 510(k), De Novo, or PMA — along with any device-specific guidance documents that govern the submission.
For novel technologies without a close analog, FDA's review may draw on recent enforcement actions, warning letters, and classification orders to determine which class best matches the device's risk profile and intended use. The written response FDA issues is advisory — it reflects FDA's current position but can be updated if the device description changes materially before submission. ADB's 513(g) packages are structured to anchor FDA's review to the most favorable classification interpretation that is accurately supported by the device's characteristics.
A 513(g) request and a Pre-Submission (Q-Sub) meeting request serve different purposes and are not substitutes for each other. A 513(g) answers the threshold question: what class is this device, and what pathway applies? A Q-Sub meeting addresses downstream questions: how should I design my testing? What predicate is FDA likely to accept? What does the IDE require? You cannot get useful Q-Sub feedback on a 510(k) strategy before you know you're in a 510(k) pathway — so if classification is genuinely uncertain, 513(g) comes first.
In practice, many companies combine both in sequence: a 513(g) to establish class and pathway, then a Q-Sub to get feedback on the submission strategy and testing plan. ADB coordinates the sequencing and timing of both to minimize total time from development to first FDA interaction to submission.
FDA's published target for responding to a 513(g) request is 60 calendar days from receipt. In practice, straightforward classification questions on well-described devices that clearly fall into an existing product code typically receive responses within 60–75 days. More complex requests — novel mechanisms of action, combination product issues, or intended use ambiguities — may trigger an FDA request for additional information, which resets the clock and can extend the timeline to 90–120 days.
The user fee for a 513(g) request must accompany the submission. ADB manages submission logistics, fee payment, and FDA correspondence tracking from submission to final response. We also analyze the FDA response in the context of your development stage and prepare a written regulatory strategy summary that translates the classification outcome into a concrete development roadmap.
A 513(g) request asks FDA to formally classify your device and identify applicable requirements — it produces a written regulatory status determination. A Q-Sub requests FDA feedback on specific questions about a submission pathway, testing approach, or study design. The two can be used together.
FDA's target response time for 513(g) requests is 60 days from receipt. FDA may request additional information that extends this window. Responses on straightforward classification questions typically arrive within 60–90 days of submission.
No — FDA's 513(g) response is not a legally binding classification order. However, it reflects FDA's current regulatory position and carries significant practical weight in your submission strategy and investor due diligence. Decisions made consistent with a 513(g) response are defensible.
Your submission must include a device description, intended use statement, specific questions for which you seek FDA's determination, and the user fee payment. The quality of your device description and question framing directly determines the utility of the response.
A 513(g) request asks FDA to provide a written opinion on the classification of a device and the regulatory requirements that apply to it — without committing to a specific submission pathway.
If you're uncertain whether your device is Class I, II, or III, file a 513(g) first. The written response becomes an exhibit in your subsequent Pre-Sub or 510(k), strengthening your regulatory strategy.
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Classification determines the submission pathway, the review standard, and the development program required. Getting it right at the start is far less expensive than discovering you're in the wrong pathway after a 510(k) submission has been filed.