On August 2, 2021, FDA issued a final rule amending its drug and medical device regulations describing the types of evidence that FDA considers relevant to determining a product’s “intended use.” The concept of intended use is a cornerstone of FDA’s regulatory scheme that determines whether and how the Agency regulates a product as a drug or device. This final rule represents the culmination of a nearly six-years-long rulemaking process that generated extensive comments from stakeholders. Most significantly, the final rule clarifies that a firm will not be regarded as intending an unapproved new, or off-label, use for a drug or device based solely on that firm’s knowledge that the product was prescribed or used by health care providers for the use. More generally, FDA has made clear that it will continue to take a broad view of what evidence, including manufacturer communications and other information about the product, may be considered when determining intended use. The amended regulations also will expressly state for the first time that the “design or composition” of an article may be relevant to determining intended use.