All medical devices sold in the United States are regulated by the U.S. Food and Drug Administration (FDA). As such, any medical device manufactured, repackaged, relabeled, or imported by a company to sell in the U.S. must meet FDA regulations.
The FDA defines a medical device as "an instrument, apparatus, implement, machine, contrivance, implant, in vitro reagent, or other similar or related article including any component or accessory that is intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease, or intended to affect the structure or any function of the body." 1 That definition applies equally to Class I, Class II, and Class III devices.
The range of medical devices regulated is immense. Such things as pacemakers, cardiovascular stents, respiratory ventilators, surgical trays, breast implants, diagnostic tests (e.g., pregnancy tests, blood glucose tests, etc.), or relatively simple devices such as tongue depressors, patient scales, and elastic bandages – all require FDA approval. Regulatory policy for medical devices follows a three-tiered classification system.
| Medical Device Class | Class I | Class II | Class III |
|---|---|---|---|
| Risk Level | Low to moderate | Moderate to high | High |
| Regulatory Pathway | General Controls (most are exempt from premarket notification) | General Controls + Special Controls; typically a 510(k) premarket notification | General Controls + Premarket Approval (PMA) |
| Common Examples | Elastic bandages, bedpans, tongue depressors, manual stethoscopes | Powered wheelchairs, pregnancy test kits, infusion pumps, contact lenses | Implantable pacemakers, heart valves, breast implants, deep-brain stimulators |
They are, simply, Class I, II, and III. Though the policy is straightforward enough, there are challenges. The FDA has classified around 1,700 different generic types of devices 2. These are grouped into 16 medical panels 2, which are then assigned to one of the three regulatory classes to determine the level of control necessary to ensure the safety and effectiveness of the device.
What then determines if your medical device is Class I, II, or III? The answer is risk.
Each medical device is classified by the risks associated with the device. The higher the class number, the greater the regulatory control, which further defines the regulatory requirements for a general device type.
Classification is determined not only by what risk the device poses to the patient and/or the user, but also the intended use of the device, along with any specialized indications for its use. For example, a standard scalpel may have the intended use to cut tissue of a patient, but a manufacturer may have a specialized scalpel specifically designed to make incisions in the cornea, which may affect its classification.
With that framework in mind, let's take a closer look at each of the three classifications of medical devices and what they mean for manufacturers.
A Class I medical device is one that poses a low to moderate risk to the patient and/or user. Today, 47% of medical devices fall under this category, and 95% of these are exempt from the regulatory process 3.
If a device falls into a generic category of exempted Class I devices, a premarket notification application and FDA clearance are not required before marketing the device in the U.S. However, the manufacturer is required to register their establishment and list their generic product with the FDA.
Class I devices are still subject to the FDA's General Controls, i.e., baseline requirements covering establishment registration, device listing, labeling, and Good Manufacturing Practices under the Quality System Regulation (21 CFR Part 820). The bar is lower than for Class II or Class III, but it isn't zero.
Examples of Class I medical devices include:
Class II medical devices carry a moderate to high risk to the patient or user. Around 43% of medical devices fall under this category 3. In fact, most medical devices on the US market are considered Class II devices.
In addition to the general controls required of all classes, Class II devices must also meet special controls. These can include specific labeling requirements, mandatory performance standards, postmarket surveillance, patient registries, and FDA guidance documents.
Most Class II medical devices reach the market through the 510(k) premarket notification pathway, in which the manufacturer demonstrates that their device is "substantially equivalent to a legally marketed predicate device," in other words, is it similar in safety and intended use to a device already on the market.
Examples of Class II medical devices include:
Class III medical devices are those that pose a high risk to the patient and/or user. These devices usually sustain or support life, are implanted, or present a potential unreasonable risk of illness or injury. They represent roughly 10% of medical devices regulated by the FDA 3.
Because of elevated risks, Class III devices require the most rigorous pathway: they must go through Premarket Approval (PMA).
The PMA process requires manufacturers to submit clinical evidence demonstrating that the device is safe and effective for its intended use. This is a more thorough review process than the 510(k) pathway used for most Class II devices. PMA review is also considerably longer and more resource-intensive than a 510(k), and approval comes with ongoing post-approval study and reporting obligations.
Examples of Class III devices include:
Understanding where your product falls within the FDA's medical device classes is, foremost, a regulatory checkbox, but also a significant factor that shapes design, material selection, documentation, and, ultimately, your manufacturing partner selection.
A misclassified device can mean months of rework and delayed launches, with costs escalating at every turn. Getting the classification right from the start – and partnering with a manufacturer that understands what each class demands – is one of the most practical ways to protect your timeline and budget.
BMP Medical is an FDA-approved original equipment manufacturer of medical devices. As part of our validation services, we advise and assist OEMs across the medical market. We help them understand the distinctions between the different medical device classifications and how they can influence the entire product development lifecycle.
Whether you're developing a Class I, II, or III medical device – or aren't sure about classification yet – our team can help you build a compliant, scalable manufacturing plan.
Contact BMP Medical today to schedule a consultation with our regulatory and manufacturing experts.
References:
