Substantial Equivalence
The legal standard a 510(k) device must meet versus a predicate.
Definition
A device is substantially equivalent if it has the same intended use as the predicate and either the same technological characteristics, or different technological characteristics that do not raise different questions of safety and effectiveness, with performance data demonstrating equivalent safety and effectiveness. FDA makes this call in the 510(k) review by comparing the new device against the chosen predicate, point by point. A 'not substantially equivalent' finding places the device in Class III by default, which usually means pursuing De Novo classification or a PMA instead.What this means in practice
Substantial equivalence is the legal foundation of the 510(k) pathway. FDA decisions hinge on careful predicate selection and side-by-side comparisons of indications, technology, and performance.Examples
- A manufacturer submits a 510(k) for a new surgical instrument, demonstrating its substantial equivalence to an existing, legally marketed surgical instrument by comparing materials, dimensions, and sterilization methods.
- A company develops a new in vitro diagnostic device and compares its performance characteristics, such as sensitivity and specificity, to a predicate device already cleared for the same intended use.
- A medical device company adds a new feature to an existing cleared device and provides data to show that this change does not raise new questions of safety or effectiveness, thus maintaining substantial equivalence to its own predicate device.
- •Failing to select an appropriate predicate device can lead to significant delays or rejection of a 510(k) submission.
- •Claiming substantial equivalence without robust side-by-side comparison data will result in FDA deficiencies.
- •Assuming that minor technological differences will automatically be considered substantially equivalent without justification is a common mistake.
- •Not adequately addressing new questions of safety and effectiveness raised by technological differences will prevent 510(k) clearance.
Frequently asked questions
Cross-references
Related terms
Grouped by themeEditor's picks
· Hand-selected related concepts510(k) Fundamentals
· From this learning pathThe objective intent of the manufacturer regarding the use of the device.
Pathway to classify novel low- to moderate-risk devices that lack a predicate.
Description of the disease or condition the device will diagnose, treat, prevent, cure, or mitigate.
FDA administrative decision that a submission is incomplete and won't be substantively reviewed.
De Novo & Breakthrough Pathways
· From this learning pathFDA program providing expedited review for devices that treat life-threatening or irreversibly debilitating conditions.
Product comprised of two or more regulated components - e.g., drug-device, biologic-device.
FDA's most stringent device marketing application, required for high-risk Class III devices.
Voluntary mechanism to obtain FDA feedback before a formal premarket submission.
Where this term appears across MedTech Terms.
- 510(k) FundamentalsLesson 3 of 7
- De Novo & Breakthrough PathwaysLesson 8 of 11
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Sources
3 sourcesEvery citation below opens the original document. Each is graded against our source-tier hierarchy so you can see what rests on binding law versus commentary.
- 1The 510(k) Program GuidanceTier 2 VerifiedFDAfda.gov
- 2European Commission - Medical DevicesTier 2 VerifiedEuropean Commissionhealth.ec.europa.eu
- 3IMDRF DocumentsTier 2 VerifiedIMDRFimdrf.org
Inline markers like [1] jump to the matching reference above.