company that earns premarket approval of its medical device is entitled to an extension of one patent claiming the device, to make up for some of the time it spent doing premarket research. Yet, surprisingly, a mere thirteen percent of those eligible for this extension (also known as patent term “restoration”) ask for one. In contrast, most drug companies entitled to this same patent extension ask for one. In this Article, we attribute the imbalance largely to differences between the two regulatory frameworks. In brief, because the FDA classifies and regulates devices based on what they do and how they do it, rather than by their composition, and because the device framework, unlike the drug framework, does not offer a regulatory advantage to companies that make exact copies, the most important moment in the lifecycle of a new medical device is the moment a competitor designs an alternative device that accomplishes the same end result. This can happen within a few short years. By way of contrast, for drug innovators the critical lifecycle moment is generally no earlier than expiry of the active ingredient patent, which generally happens later. In other words, medical devices have much shorter commercial lifecycles. While some suggest that medical device patents are therefore less important than drug patents, our explanation indicates only that the length of the patents is less important. Recent empirical research (Graham 2009, Simon 2020) describes the role that medical device patents play early in the product lifecycle—often before regulatory approval—focusing on the foundation they provide for efficient exchanges of information and market transactions. Our paper builds on their work by (1) offering a description, grounded in reflection on the essential nature of the two regulatory frameworks, of the differing roles play by drug and device patents, and (2) offering an additional supportive data point in that, although device patenting is steadily increasing, eligible device companies generally do not bother seeking patent extensions. It also illustrates the role that regulatory design can play in dictating the value of patent length, which should be important for policy planners.