The US Mint has stopped producing pennies due to their high production cost, which is nearly four cents per coin. The last penny was minted in Philadelphia, and although the coin will remain legal tender, its removal from circulation is causing problems for retailers. Some merchants plan to round prices to the nearest nickel, while others may face legal trouble for doing so. The discontinuation of the penny has been described as chaotic, with no clear guidance for retailers on how to handle the change.