Predicate Device

Planning to market your new Class II medical device in the USA?

Then you must have the right predicate device and proper documentation, to support the U.S. Food and Drug Administration (FDA) substantial equivalence, in place.

If the FDA determines that your class II device is substantially equivalent to the predicate device you selected then you can get a medical device clearance for sale in America.

But what is a predicate device?
How can you select the right one?

If you have these questions in mind, then this blog is going to answer all of them.

What is a Predicate Device?

According to the “Medical Device Regulations”, a predicate device can be a device:

⦿ Proved to be substantially equivalent through 510k.
⦿ Legally marketed before the establishment of Medical Device Amendments (MDA) on May 28, 1976.
⦿ Recategorize from Class III to Class II or I.
⦿ Passed through the De Novo classification process for marketing. 

Most commonly, a predictive device (or 510k predicate) refers to an FDA-approved and legally marketed device that you can use for comparing your Class II medical device with, demonstrating similarities to get 510k clearance. This comparison is commonly known as FDA substantial equivalence. Although both devices need not be identical, the pre-approved device can provide evidence against the reliability and safety of your medical device. 

What are the Types of Predicate Devices?

The two types of predicate devices include: 

⦿ Pre-amendment devices: Pre-amendment devices refer to those legally marketed devices before the establishment of the MDA. 
⦿ Post-amendment devices: Post-amendment devices refer to those devices that have gone through pre-market approval or 510k clearance for legal marketing in the USA.

How can you use a Predicate Device to Establish Substantial Equivalence?

The 510k clearance process requires a clear demonstration of substantial equivalence so that you can legally market your device in the US market. For establishing substantial evidence, To establish substantial equivalence, you must show that your device has effectiveness, a purpose, and safety, to the predicate device. To ensure FDA substantial equivalence, your device must have: 

⦿ Characteristics and features that do not lead to effectiveness and security problems
⦿ Related technical characteristics and features as the 510k predicate 
⦿ Same intended use as the 510k predicate

How does the FDA use a Predicate Device to Determine Substantial Equivalence?

The FDA follows the steps given below to determine substantial equivalence: 

⦿ Step 1: The FDA checks if the new device and the predicate device have the same intended use and ensures any differences in technology don’t affect safety and effectiveness.

⦿ Step 2: If step 1 is cleared, the FDA evaluates if the new device is as safe and effective as the 510k predicate. They review performance data for both devices, including their biocompatibility, engineering tests, scientific methods, software validation, and sterility. 

Can the FDA declare No Substantial Equivalence despite providing a 510k Predicate?

Yes, it can. According to the FDA’s official website, 3.5% of 510(k) submissions resulted in No Substantial Equivalent (NSE) between 2010 and 2011. The FDA can declare NSE for your device during the following instances: 

⦿ No 510k predicate: When you fail to provide a suitable predicate device for your case, the FDA declares NSE. 

⦿ Different intended use: If the intended purpose of your device is different from the predicate, the FDA proclaims NSE for your device. This happens when the FDA finds a change in your device’s use indications, concluding it to have a different intended purpose. 

⦿ Dissimilar technology: When the technology used in your device differs from the predicate, the FDA marks NSE for your device. 

⦿ No/Inadequate/Irrelevant Performance Data: The FDA can announce NSE for your device if you fail to provide or present inadequate performance data in your 510k submission. The FDA may also conclude NSE if the provided data fails to demonstrate the similarity in performance between your device and the predicate. 

⦿ Split Predicate Usage: Split predicate refers to predicate devices with different purposes and usage. The FDA prohibited medical device manufacturing companies from demonstrating substantial equivalence using split predicates in 2014. 

What happens to No Substantial Equivalent Devices?

NSE has two types of determinations and subsequent consequences. Those include:

⦿ Category 1: The first category includes decisions like no predicate device, a different intended use, or dissimilar technology that raises safety and effectiveness concerns. The FDA will likely ask you to address these concerns in a Request for Additional Information letter. 

⦿ Category 2: The second category includes devices with insufficient information to show they are substantially equivalent to the predicate device. The FDA will request additional performance testing data. If you don’t provide this information, your submission may be put on hold.

Both determinations provide you with ways to bring your medical device to the US market legally. 

Is there an Alternative to Market an NSE Device Legally?

Despite being marked as NSE, you can:  

⦿ Resubmit a different 510k with information and data that address the FDA’s questions from the previous review
⦿ Submit a PMA (pre-market approval application)
⦿ Put an application for a reclassification petition
⦿ Apply for the De Novo Classification process to request a class I or II designation for your device. 

You may collaborate with a medical device regulatory consultant to ensure FDA substantial equivalence for your device. These professionals have years of experience and the knowledge to guide you in the right way, leading to 510k clearance easily and efficiently.

Where to find a Predicate Device?

The FDA’s database assigns a three-letter product code to each device classification. The FDA database lists all devices cleared through the 510k process. After receiving the three-letter code, you can find details about every product, company, and trade name of competitors. This allows you to analyze and compare devices to identify a suitable predicate device.

How to Select a Predicate Device?

To select the right predicate device for 510k clearance, you should keep certain factors in mind. Try selecting a 510k predicate that has: 

⦿ Congruent purpose/usage: Try to select a 510k predicate that has a similar usage or that tends to solve similar purposes. For example, if your device is used for blood pressure measurement, try choosing a blood pressure measurement device as your predicate. 

⦿ Similar technical characteristics: Take a predicate that has technical characteristics identical to your device. These characteristics can include design, materials, labeling, and operational methods.

⦿ Biocompatibility: Confirm a predicate that aligns with the manufacturing process, raw material use, and supplementary chemicals used in your device.

⦿ Been approved recently: Due to rapid technological advancements, try to choose a predicate that the FDA has recently approved. 

⦿ The latest technology: Pick a predicate that uses the latest medical technology. 


Although the complicated 510k process is not the only way to bring your class II medical device to the market, it is one of the most commonly followed clearance processes due to its greater success rates. When it comes to the 510k process, a predicate device plays a key role in determining the clearance of your medical device. The right selection can reduce time and costs for bringing your product to the market but the wrong selection can lead to expensive and time-consuming approval processes. 

To ensure the right selection, you may take suggestions from an experienced medical device regulatory consultant. They can guide you through this complex process by helping you understand what constitutes a predicate device, selecting one with similar intended use and technical characteristics, and addressing any FDA concerns. They can also assist in navigating the FDA’s database to find relevant predicates. By leveraging their expertise, you can avoid pitfalls, streamline your approval process, and bring your device to market more efficiently and successfully.

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