Medical Device Categories Explained

By Dr. Sanchari Sinha Dutta, Ph.D.Reviewed by Danielle Ellis, B.Sc.

How are medical devices classified?
What are the basic regulatory requirements for medical device manufacturers?
Medical device classification
Class I medical devices
Class II medical devices
Class III medical devices
References 
Further reading

The U.S. Food and Drug Administration (FDA) categorizes medical devices into three classes based on the level of risk the devices pose to patients and users.

The FDA’s Center for Devices and Radiological Health is responsible for regulating firms that manufacture, repackage, relabel, and import medical devices in the United States.

How are medical devices classified?

The FDA categorizes medical devices into three classes, namely Class I, Class II, and Class III. Regulatory control increases from Class I to Class III. ¹ The agency has classified approximately 1,700 different generic types of devices and grouped them into 16 medical panels. ²

Each of these generic types of devices is assigned to one of three regulatory classes (Class I, Class II, and Class III) based on the level of control necessary to assure the safety and effectiveness of the device. ²

While the majority of Class I devices do not require Premarket Notification 510(k), the same is required for most of the Class II devices. For most of the Class III devices, Premarket Approval is a mandate. The FDA’s 510(k) clearance is required for marketing medium-risk medical devices, and Premarket Approval is required for marketing high-risk devices. ¹

The FDA’s 510(k) review process primarily focuses on investigating whether the new device is “substantially equivalent” to an existing device. This process does not generally include human clinical trials. ³

All Class III devices that are associated with a significant risk of illness or injury must go through the FDA’s Premarket Approval process. The process includes the submission of clinical trial data to the FDA in support of the safety and effectiveness of the device for its intended purpose. ¹

Non-approved high-risk devices are mostly studied under an Investigational Device Exemption that needs strict supervision by the FDA’s Center for Devices and Radiological Health as well as by the local institutional review board. ³

Medical devices that receive necessary clearance or approval from the FDA can be marketed for sale and use in the United States. ³

What are the basic regulatory requirements for medical device manufacturers?

The manufacturers of medical devices in the United States must comply with some basic regulatory requirements. The main purpose of the device classification regulation is to detect and correct device-related problems in a timely manner. ¹

Domestic manufacturers and importers of medical devices must register their establishments with the FDA electronically unless the FDA has granted a waiver. Foreign manufacturers must designate a U.S. Agent in addition to device registration. ¹

An annual verification of registration information must be conducted between October 1^st and December 31^st of each year. The FDA has introduced an establishment registration fee for most establishments since October 2007. ¹    

All manufacturers must list their medical devices with the FDA and go through the necessary processes to obtain Premarket Notification 510(k) or Premarket Approval from the FDA. Most of the Class I devices and some of the Class II devices are exempt from the Premarket Notification 510(k) submission. ¹

All methods and manufacturing facilities used for designing, purchasing, manufacturing, packaging, labeling, storing, installing, and servicing medical devices must undergo FDA inspections to ensure compliance with the Quality System requirements. ¹

Any malfunctioning of medical devices or incidence of death or severe injuries caused by medical devices must be reported to the FDA under the Medical Device Reporting Program. ¹

In Europe, medical devices are governed by two main regulations: the European Union Medical Device Regulation and the In Vitro Diagnostic Medical Device Regulation. These two regulations involve a wide-range of measures, including securing medical device-related documentation requirements, monitoring devices, and restricting and reporting substances used in device design and manufacturing. ⁴     

Medical device classification

Overall, the classification of medical devices depends on two factors, i.e., the risk associated with device usage and the intended use of the device, along with any specialized indications for its use. ²

Class I medical devices

Class I medical devices are low-risk devices that exhibit minimal potential for harm to users. These devices are mostly non-invasive and thus require the least level of regulatory control. These devices have simpler designs than Class II and Class III devices. ⁵  

About 47% of medical devices fall under this category, and 95% of them are exempt from the FDA’s regulatory process. Common examples of Class I devices include bandages, handheld surgical instruments, non-electric wheelchairs, and enema kits. ⁵

Class II medical devices

Class II medical devices pose a moderate risk to the users. These devices are more likely to come into sustained contact with a patient’s internal organs and thus require FDA’s 510(k) clearance before being marketed in the United States. ⁵

About 43% of medical devices come under this category. Common examples of Class II devices include pregnancy test kits, powered wheelchairs, computed tomography (CT) scanners, and infusion pumps for intravenous medications. ⁵

Class III medical devices

Class III medical devices are high-risk devices that are commonly used to sustain or support the life of a patient. About 10% of medical devices come under this category, and these devices exhibit a potentially unreasonable risk of illness or injury. ⁵

These devices are subjected to a robust regulatory process, which often involves obtaining FDA’s Premarket Approval. Common examples of Class III devices include pacemakers, breast implants, cochlear implants, deep-brain stimulators, heart valves, and defibrillators. ⁵    

References

1. Health C for D and R. Overview of Device Regulation. FDA. January 31, 2024. Accessed October 18, 2024. https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/overview-device-regulation

2. Health C for D and R. Classify Your Medical Device. FDA. August 14, 2023. Accessed October 19, 2024. https://www.fda.gov/medical-devices/overview-device-regulation/classify-your-medical-device

3. Jin J. FDA Authorization of Medical Devices. JAMA. 2014;311(4):435. doi:10.1001/jama.2013.286274 https://jamanetwork.com/journals/jama/fullarticle/1817798

4. Medical devices | European Medicines Agency (EMA). February 28, 2019. Accessed October 18, 2024. https://www.ema.europa.eu/en/human-regulatory-overview/medical-devices

5. Health C for D and R. Learn if a Medical Device Has Been Cleared by FDA for Marketing. FDA. Published online November 3, 2018. Accessed October 19, 2024. https://www.fda.gov/medical-devices/consumers-medical-devices/learn-if-medical-device-has-been-cleared-fda-marketing

Further Reading

• All Medical Devices Content
• How Could Sharks lead to New Medical Devices?
• The Importance of Regulating Medical Devices
• Insight into Implantable Medical Devices
• What are Medical Alert Devices?