FDA 513(g) Request for Information: 60-Day Device Classification, User Fees, and 513(g) vs. Pre-Sub

An FDA Section 513(g) Request for Information—governed by Section 513(g) of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. § 360c(g), implemented at 21 CFR § 860.120 and the December 2019 FDA Guidance FDA and Industry Procedures for Section 513(g) Requests for Information)—is a formal, user-fee-bearing regulatory submission through which a manufacturer or software developer requests a written determination from the U.S. Food and Drug Administration (FDA CDRH or CBER) regarding whether a product is a regulated medical device and, if so, its generic device class (Class I, II, or III) and applicable premarket regulatory requirements.

What Is an FDA Section 513(g) Request for Information (21 U.S.C. § 360c(g)) and What Does the FDA’s 60-Day Written Determination Provide?

Under the plain text of 21 U.S.C. § 360c(g), within 60 calendar days of receiving a written request from any person for information respecting the class in which a device has been classified or the requirements applicable to a device under the FD&C Act, the FDA must issue a written statement specifying:

1. Device Jurisdiction Determination: Whether the product meets the statutory definition of a device under Section 201(h)(1) of the FD&C Act (21 U.S.C. § 321(h)(1)) or whether it is excluded from the device definition—such as qualifying as a non-device software function under Section 520(o) of the FD&C Act (21 U.S.C. § 360j(o)) (brought in by the 21st Century Cures Act for administrative, healthy lifestyle, electronic patient record, MDDS, or non-device clinical decision support [CDS] tools).
2. Regulatory Classification & Regulation Number: If the product is a regulated medical device, the applicable 21 CFR classification regulation (e.g., 21 CFR § 892.2080 for radiology CADt software), 3-letter FDA product code, and risk class (Class I, Class II medical device, or Class III).
3. Applicable Premarket Pathway & Exemptions: Whether the device is 510(k)-exempt (subject to 21 CFR xxx.9 limitations on exemptions), requires a 510(k) premarket notification, is unclassified/post-amendments requiring a De Novo classification request (Section 513(f)(2)), or requires an FDA Premarket Approval (PMA), as well as whether FDA currently exercises enforcement discretion over the product category.

Required Contents of a Section 513(g) Submission

Under the 2019 FDA 513(g) Guidance, a complete submission (submitted electronically via the CDRH Customer Collaboration Portal / eSTAR or eCopy) must contain only descriptive and labeling materials—never clinical study data or bench test reports:

• Cover Letter: Explicitly identifying the submission as a “Section 513(g) Request for Information” for a single product (FDA does not permit bundling multiple distinct products or unrelated intended uses in one 513(g)).
• MDUFA User Fee Cover Sheet (Form FDA 3601): Proof of payment of the mandatory Section 513(g) user fee under the Medical Device User Fee Amendments (MDUFA) (Section 738(a)(2)(A)(ix) of the FD&C Act), with a 50% small-business fee reduction for companies certified by FDA as having ≤$100 million in gross receipts/sales.
• Complete Device Description: Materials, hardware components, software architecture, algorithm inputs/outputs, operating principles, and how the product interacts with the user and patient.
• Clear Statement of Intended Use / Indications for Use: The disease or condition, target patient population, intended user (e.g., specialist physician vs. lay consumer), and clinical setting.
• Proposed Labeling and Promotional Materials: Draft user manual/IFU, UI screenshots, marketing claims, and website copy (because under 21 CFR § 801.4, objective intent is determined from labeling and promotional claims).

What Is the Strategic Difference Between Filing a User-Fee 513(g) Request for Information vs. a Free Pre-Submission (Q-Sub) or Self-Documenting Under Section 520(o)?

Regulatory affairs teams for digital health, wearable diagnostics, and clinical AI software frequently weigh three options when a product’s regulatory status is ambiguous. Crucially, the FDA’s Q-Submission guidance explicitly states that FDA will not determine whether a product is a medical device or assign a device classification inside a free Pre-Submission (Q-Sub); classification and jurisdiction requests are routed strictly to the fee-bearing 513(g) pathway (or to the Office of Combination Products via a Request for Designation [RFD] when drug-device vs. biologic primary mode of action is in question):

Dimension	Section 513(g) Request for Information	FDA Pre-Submission (Q-Sub)	Internal Regulatory Assessment (Letter to File)
Primary Question Answered	“Is our product a regulated medical device, what Class (I/II/III) and regulation apply, or is it a non-device / enforcement-discretion product?”	“Assuming our product is a regulated device, are our proposed clinical trial protocol, bench tests, or predicate device acceptable for 510(k)/De Novo/PMA?”	“Does our software clearly satisfy all statutory criteria for a non-device function under Section 520(o) or Class I 510(k)-exempt regulation?”
FDA User Fee	Yes (Mandatory MDUFA V user fee; 50% discount for qualified small businesses; refunded only if not accepted for review)	Free ($0) (No MDUFA user fee for Pre-Submissions or Study Risk Determination Q-Subs)	$0 FDA fee (Internal regulatory affairs / legal counsel documentation cost only)
Review Timeline & Format	60 calendar days statutory written response only (no teleconference or interactive meeting included)	70 calendar days (or 5 days prior to scheduled 1-hour teleconference/in-person meeting)	Immediate internal sign-off; updated whenever software features or marketing claims change
Review of Test Data / Protocols	Prohibited: FDA will not review bench testing, animal data, clinical protocols, or software verification inside a 513(g)	Core purpose: Specifically designed to review clinical protocols, validation plans, and predetermined change control plans (PCCPs)	Documents internal verification/validation and labeling boundaries
Legal Binding Status	Non-binding agency guidance based on submitted facts (21 CFR § 860.120(b)); does not constitute final premarket clearance	Non-binding written feedback and meeting minutes recorded in official Q-Sub file	Internal compliance defense record for investor/hospital due diligence and FDA inspection

When Should a Digital Health or Clinical AI Developer Use a 513(g) to Clarify Device Status and Class I/II/III Pathway?

Because a Section 513(g) carries a user fee, provides no interactive meeting, and creates an official written FDA record based strictly on the submitted labeling, experienced regulatory teams use a 513(g) selectively:

1. Borderline Multi-Function Digital Health Platforms (Section 520(o)(2)): When a software platform combines non-device wellness/administrative modules with borderline clinical risk-scoring or triage visualizations and hospital procurement, venture investors, or Tech E&O underwriters demand an official written FDA letter confirming that the product is either outside Section 201(h) or subject to FDA enforcement discretion.
2. Novel Hardware or Sensor Accessories Without an Obvious 21 CFR Regulation: When a developer needs official written confirmation from CDRH that no existing Class I/II classification regulation covers their novel diagnostic device—establishing the written foundation to proceed directly to a De Novo classification request without first having a 510(k) rejected as Not Substantially Equivalent (NSE).
3. When NOT to File a 513(g): If a developer already knows their clinical AI software is a regulated device (for example, an image-analyzing lesion detector that clearly fails Prong 1 of Section 520(o)(1)(E)) and wants to discuss predicate selection, De Novo special controls, or clinical validation endpoints, filing a 513(g) wastes 60 days and a user fee—because the 513(g) letter will simply state that the product is an unclassified/Class II device requiring a 510(k) or De Novo. In that scenario, the developer should file a free Pre-Submission (Q-Sub) directly.

Frequently Asked Questions

What is an FDA Section 513(g) Request for Information (21 U.S.C. § 360c(g)) and what does the FDA’s 60-day written determination provide?

A Section 513(g) Request for Information is a formal, fee-bearing submission asking the FDA to state in writing—within 60 calendar days—whether a product is a regulated medical device under Section 201(h) of the FD&C Act and, if so, its generic device classification (Class I, II, or III), 21 CFR regulation number, product code, and required premarket submission pathway (510(k), De Novo, PMA, or 510(k)-exempt).

What is the strategic difference between filing a user-fee 513(g) Request for Information vs. a free Pre-Submission (Q-Sub) or self-documenting a non-device status under Section 520(o)?

A 513(g) requires a MDUFA user fee, offers a written determination in 60 days with no interactive meeting, and answers only whether a product is a device and what class/pathway applies (prohibiting review of clinical protocols or test data). A Pre-Submission (Q-Sub) is free and includes an interactive FDA meeting to review clinical/bench testing protocols, but FDA will not make formal device vs. non-device jurisdiction or classification determinations in a Q-Sub.

When should a digital health or clinical AI developer use a 513(g) to clarify whether a software function is a regulated medical device and its Class I/II/III pathway?

Digital health developers use a 513(g) when a software product sits on the regulatory boundary between non-device Clinical Decision Support (Section 520(o)(1)(E)), enforcement discretion, and regulated SaMD—especially when hospital buyers or investors require an official FDA letter confirming regulatory status, or when confirming that a novel device has no existing classification regulation before preparing a De Novo submission.