Learn the difference between the terms FDA-cleared and FDA- approved

Understand the categories and pathway for FDA review for Class I, II and III medical devices

Define 510k clearance, premarket notification, iCGM and ACE pump

Read on for a quick tutorial on how the U.S. Food and Drug Administration (FDA) classifies, reviews and allows any and all medical devices to enter the U.S marketplace. Plus, catch up on how FDA has recently opened the door to integrated and interoperable diabetes devices.

Device Classification Determines Review

Most of the work to review medical devices is conducted within the FDA’s Center for Diagnostics and Radiological Health, abbreviated CDRH. CDRH reviews medical devices through one of several pathways. The pathway CDRH uses for review is based on the level of control needed by the person operating the device to assure the safe and effective use.1 Stated more succinctly: how much potential the device has to cause harm to the user.

  • 510k-exempt: very low risk devices. These do not require FDA review prior to being made available. Example: insulin pen clip that does not offer bolus doses decision support
  • Class I: low risk devices. Examples: bandages, nonelectric wheelchairs
  • Class II: moderate risk devices. Example: blood glucose monitors (BGM), older insulin pumps without Continuous Glucose Monitor (CGM) integration, smart insulin pens that can integrate with CGM, such as: Medtronic’s InPen and Bigfoot’s Unity System
  • Class III: higher user risk. Example: insulin pumps that integrate with CGM and assist in minimizing hyperglycemia and hypoglycemia

When a manufacturer submits a Class I or II device to CDRH for review, they submit what is called a Premarket Notification, also know as a 510k. If the manufacturer receives a positive review of their Class I or II device, it receives “clearance.” The device is then known as “FDA-cleared.”

When a manufacturer submits a Class III device they submit a Premarket Approval Application, abbreviated as a PMA. Class III devices undergo a more rigorous review at CDRH. This determines reasonable assurance of safety and effectiveness. If the manufacturer receives a positive review of their Class III device, it receives “approval.” The device is then known as “FDA-approved.”

FDA Opens the Door for Innovation in Diabetes Care

Over the past few years FDA’s CDRH has, through several new authorizations, has opened the door to diabetes device innovation, which includes greater device integration and interoperability (see definition below).

For starters, in 2018 FDA cleared the first integrated CGM (iCGM). An iCGM is integrated with other compatible medical devices and electronic interfaces, such as automated insulin dosing systems, insulin pumps, BGM or other electronic devices used for diabetes management. With this authorization FDA initially cleared the Dexcom G6 iCGM.2 FDA also began classifying the iCGM as a Class II device with this authorization. (Older CGM systems were classified as Class III devices and required use of FDA’s premarket approval pathway.)

Next, in late 2019, FDA authorized the Tandem Diabetes Care Control-IQ technology. With this authorization FDA allowed, “substantially equivalent controller technologies…to go thru the 510k review process” (see above)3. This authorization opened the door to the first interoperable, automated glycemic controller device that automatically adjusts insulin delivery by connecting to an alternate controller-enabled insulin pump (abbreviated ACE pump) and integrated continuous glucose monitor (iCGM) (defined above). The Tandem Diabetes Care t:slim X2 Control-IQ Technology device was reviewed through a new route called the De Novo premarket review pathway established to enable faster innovation, less regulatory burden, more component flexibility, and more device choices. The FDA defined new device categories with this new pathway, including an interoperable automated glycemic controller device (referred to as icontroller). The icontroller automatically adjusts insulin delivery by connecting to an ACE pump and the iCGM.

Lastly, one other addition. In early 2019 FDA set a fast-track process in place referred to as the Breakthrough Devices Program.4 This program provides priority review to help people gain access to breakthrough technologies faster. In the diabetes area, Medtronic received this designation in 2019 for its Personalized Closed Loop (PCL) insulin pump system.5 The update on the PCL straight from Medtronic is that the PCL will be more advanced than MiniMed 780G. PCL is a future pump system currently in feasibility trials. (The MiniMed 780G was submitted to FDA by Medtronic in April 2021 and is currently under review.)

These important and numerous changes are putting the pieces in place for so-called, “device interoperability.” This will introduce the ability to purchase different device components (based on the user’s device preferences), and not to have to purchase the complete system from just one manufacturer. In practical terms, Brandon Arbiter, VP of product and business development at Tidepool and person with diabetes, makes this analogy to explain “device interoperability” for people with diabetes. “When I buy a new smartphone, I can use it with my favorite Bluetooth headphones and all my favorite apps. Even if i switch from iPhone to Android, I can keep using the same Bluetooth headphones and apps, because they’re interoperable. When I buy an interoperable insulin pump, I want to be able to connect it to the CGM and apps that work best for me. If one component stops working well for me, I can replace it and continue to use the other components I know and love.” Arbiter adds, “Diabetes is not a one-size-fits-all disease. When a person with diabetes can choose and connect the components that work best for them, they will get better outcomes, and that’s why interoperability is so important for us.”


  1. FDA. Classify your medical device. https://www.fda.gov/medical-devices/overview-device-regulation/classify-your-medical-device. Accessed June 10, 2021.
  2. FDA. FDA authorizes first fully interoperable CGM system, streamlines review pathway for similar devices. https://www.fda.gov/news-events/press-announcements/fda-authorizes-first-fully-interoperable-continuous-glucose-monitoring-system-streamlines-review. Accessed June 10, 2021.
  3. FDA. FDA authorizes first interoperable, automated insulin dosing controller designed to allow more choices for patients looking to customize their individual diabetes management device system. https://www.fda.gov/news-events/press-announcements/fda-authorizes-first-interoperable-automated-insulin-dosing-controller-designed-allow-more-choices. Accessed June 10, 2021.
  4. FDA. Breakthrough device program. https://www.fda.gov/medical-devices/how-study-and-market-your-device/breakthrough-devices-program. Accessed June 10, 2021.
  5. Medtronic. Medtronic Receives FDA Breakthrough Designation for Developing Personalized Closed Loop Insulin Pump System for Diabetes Management. https://newsroom.medtronic.com/news-releases/news-release-details/medtronic-receives-fda-breakthrough-designation-developing. Accessed June 10, 2021.