Apple has officially confirmed that it is launching its iPhone trade-in program today at its U.S. retail stores, according to a Tweet from CNBC’s Jon Fortt. While a number of details on the program have leaked over the past few months, today’s statement is the first public confirmation by Apple that the program exists. Under the program, users can receive a gift card in exchange for their older devices, although the gift card must immediately be used toward the purchase of a new iPhone. Trade-in values are based on a number of criteria, including model and capacity and physical condition.