Class III (General Controls and Premarket Approval): Class III devices tend to be somewhat complex, life-sustaining or life-supporting, and a performance failure could result in serious injury or death to the user. For example, a heart pacemaker that is implanted in the body would be a Class III device. New devices that are not found by FDA to be "substantially equivalent" to currently marketed devices are automatically Class III.
Class II (General Controls and Special Controls): Class II devices are devices with some complexity that, if they fail, could cause injury to the patient. Daily-wear soft contact lenses are a common example of a Class II device. Over half of all medical devices are Class II.
Class I (General Controls): Class I devices are relatively simple, low risk devices, which, even if they fail, will not likely injure the user. Common devices such as toothbrushes and adhesive bandages are examples of Class I medical devices.
Unclassified: For UDI, these products are to be treated as Class 1
Exempt: For UDI, these products are exempt from receiving the 2D and linear/stacked concatenated.
Retail: For UDI, these products will keep the retail UPCA barcode on the inner most level. The intermediate and outer levels will receive the linear/stacked concatenated.