evidence: McDonald's Is Giving Away Free Big Macs, As Long As You Have This One Thing If you haven't already heard, the McDonald's Big Mac is celebrating its big 5-0 on Thursday, Aug. 2. The Golden Arches is kicking off the famed burger's milestone birthday with a special form of payment, so you can come back for a free Big Mac at a later date. Not just anyone is privy to receiving the fast food gold coins, though. Like all good deals, there are a few stipulations to scoring the money-saving change. What is the McDonald's MacCoin? The celebratory currency will get you free food. The McDonald's Big Mac knows how to party. The burger with that tasty special sauce turns 50 at the beginning of August, and McDonald's is giving customers a chance to keep the celebration going all week long. Starting during the lunchtime hours of Thursday, Aug. 2, anyone who orders a Big Mac will receive a free MacCoin with their purchase. Move over Bitcoin, because the MacCoin is here to get you another two-patty burger for free. That's right, by purchasing one Big Mac, you can get another one at no cost with your MacCoin. There are a few things to note, though. In order to get a MacCoin with your Big Mac purchase, you must place your order at one of the 14,000 participating McDonald's locations in the United States, according to McDonald's. With so many stores, you should have no problem securing your prized MacCoin. The coins are available as long as supplies last.