Introduction: Each year, people with diabetes and their insurers or governments spend billions of dollars on blood glucose monitors and their associated components. These monitors have evolved substantially since their introduction in the 1970s, and manufacturers frequently protect original medical devices and their modifications by applying for and obtaining patent protection.

Research design and methods: We tracked the product iterations of five widely used blood glucose monitors-manufactured by LifeScan, Dexcom, Abbott, Roche, and Trividia-from information published by the U.S. Food and Drug Administration (FDA), and extracted relevant U.S. patents.

Results: We found 384 products made by the five manufacturers of interest, including 130 devices cleared through the 510(k) pathway, 251 approved via the premarket approval (PMA) pathway or via PMA supplements, and three for which de novo requests were granted. We identified 8095 patents potentially relevant to these devices, 2469 (31%) of which were likely to have expired by July 2021.

Conclusions: Manufacturers of blood glucose monitoring systems frequently modified their devices and obtained patent protection related to these device modifications. The therapeutic value of these new modifications should be critically evaluated and balanced against their additional cost. Older glucose monitoring devices that were marketed in decades past are now in the public domain and no longer protected by patents. Newer devices will join them as their patents expire. Increased demand from people with diabetes and the health care system for older, off-patent devices would provide an incentive for the medical device industry to make these devices more widely available, enabling good care at lower cost when such devices are substantially equivalent in effectiveness and safety. In turn, availability and awareness of older, off-patent devices could help stimulate such demand.