510(k) and Substantial Equivalence: Similar Is Not Cleared
A 510(k) is not a question of whether a product looks like another product on the market. It is FDA’s determination that a specific device is substantially equivalent to a legally marketed predicate device for a specific intended use. Whether a seller needs one, and whether a similar product on a marketplace tells you anything about your own, depends on the facts and on the role you play.
Why does “substantially equivalent” not mean “similar”?
In everyday talk, a product is similar to another if it looks, works or is used alike. In the 510(k) pathway, the comparison is narrower and more technical. FDA asks whether the new device has the same intended use as a legally marketed device (the predicate) and either has the same technological characteristics or has different characteristics that do not raise different questions of safety and effectiveness, with data showing the device is as safe and effective as the predicate. A product can look nearly identical to a cleared one and still differ in a way that matters, such as materials, energy source, software or the claims made for it. A product can also look quite different and still be comparable. The word the agency uses is a legal conclusion, and it is reached device by device.
Why the predicate matters, and why it can be a trap
The predicate is a device that is legally marketed. That means a device cleared through a 510(k), a device granted marketing authorization through De Novo, a device on the market before the 1976 device amendments or one reclassified into a lower-risk class. A seller who sees a competitor selling a product on a marketplace may assume it is cleared. It might be, or it might be exempt, or it might be on sale without a clearance it needed. Another seller’s listing is not evidence that the product is legal, and it is not a predicate in the regulatory sense unless it is itself legally marketed. A seller who matches a competitor’s product and claims inherits the competitor’s regulatory position, whatever it is.
Why timing and triggers depend on the facts
The regulation says a premarket notification is generally due at least 90 days before a device is introduced into commercial distribution. It lists situations that trigger one: a device that is not substantially equivalent to a pre-1976 device or a reclassified one, the first introduction of a device by a person required to register, and a significant change or modification in design, components, method of manufacture or intended use (21 C.F.R. § 807.81). Whether a change is significant, and whether a product is a new device at all, is a judgment that depends on the details. Two sellers of products that sound alike can land on opposite sides of that line.
Why the seller’s role changes the answer
FDA’s own materials describe who submits: domestic manufacturers, specification developers, repackagers or relabelers who significantly change labeling or the condition of the device, and foreign manufacturers or their U.S. representatives. They also describe firms that generally do not, such as contract manufacturers, distributors of another firm’s domestically made device and most repackagers. An online business that private-labels a product made elsewhere may be a specification developer or a relabeler, which can put the brand owner, and not the factory, in the position of needing the clearance. A seller that only resells another firm’s cleared device is often in a different position. The label on the box and the contracts behind it can decide which situation applies.
Why exemption is not a blanket pass
Some devices are exempt from a 510(k). The statute and regulations allow exemptions for certain lower-risk classes, but they carry limits. An exemption can be lost where the device is intended for a use of substantial importance in preventing impairment of human health or presents a potential unreasonable risk of illness or injury, and each device part of the regulations has its own limitations. Being exempt from a 510(k) also does not remove other obligations, such as registration and listing, labeling or quality-system duties that may apply to the seller. An exemption is therefore a starting point for analysis and not an answer.
Why a lawyer, and why not only a lawyer
The question has legal parts (what the regulation covers, what a claim does to a product’s category, what a contract with a manufacturer assigns) and technical parts (whether the device’s technology and testing support a comparison). We handle the legal part, which includes what a claim does to the product’s category and what your manufacturing contract assigns, and we coordinate the technical part with regulatory and testing specialists. If a marketplace has asked for a clearance letter, a warning letter has arrived or a competitor has complained, the analysis is the same, but the time to act is shorter. For the wider picture, see FDA registration and clearance and compliance with laws for online businesses.
How do I get started?
Contact us. Tell us the product, how it is made and sold and any notice you have received, and we will tell you whether we can help.
Realistic expectations
- We cannot guarantee that FDA clears any device, that a product is or is not subject to a 510(k) or any particular regulatory or marketplace outcome.
- FDA rules differ by device type, and this article does not tell you whether your product needs a clearance.
- Rules and agency guidance change, so check the current requirement for your product.
- Past results do not guarantee similar outcomes.
Frequently asked questions
What does substantially equivalent mean to FDA?
Does a similar product on Amazon show that mine needs no clearance?
Who files a 510(k) when a brand uses a contract manufacturer?
Does an exempt device avoid all FDA requirements?
Can changing a cleared product trigger a new 510(k)?
Related pages
FDA registration and clearance
Registration, listing and clearance, and how they differ.
Compliance with laws
FTC, FDA, EPA and other rules.
Packaging compliance
Labels and the name on the package.
FTC reviews and claims
Claims and endorsements.
Sources and notes
- 21 C.F.R. § 807.81. 21 U.S.C. § 360(k), (l) and (m). FDA, Premarket Notification 510(k) page.
Talk to a lawyer about a device or a 510(k) question
Bring the product, the contracts behind it and any notice from a marketplace or regulator.
Rafelson Law PLLC · 2255 Glades Rd, Suite 319A, Boca Raton, FL 33431
Phone: (833) 326-6529 · Email: [email protected]
Informational only; not legal advice. Contacting us does not create an attorney-client relationship, which begins only with a signed written engagement. Please do not send confidential details until we confirm in writing that we represent you. If you face a deadline, say so in your first message.