The first few iPhones were available in the U.S. only through AT&T. Verizon Wireless broke AT&T's exclusive grip on the iPhone last year, and other phone carriers have since started selling it as well.
Apple hasn't announced all the carriers that will get the new iPhone 5. Apple's online store names AT&T, Sprint and Verizon, though many smaller carriers have been selling it directly.
Here's a look at how iPhone availability has expanded in the U.S.:
— COMING TO NO. 1: AT&T Inc. was the only U.S. carrier offering the iPhone when the first model came out in 2007. It lost its exclusive status in February 2011 when Verizon Wireless, the nation's top wireless carrier, started selling the iPhone.
— ANOTHER NATIONAL CARRIER: Sprint Nextel Corp., the No. 3 carrier, also got the iPhone, starting last October with Apple Inc.'s introduction of the iPhone 4S. It also sells the iPhone 4 with AT&T and Verizon Wireless.
— REGIONAL OFFERING: C Spire Wireless, a small company that provides service in Mississippi and surrounding states, started selling the iPhone late last year. It bypassed larger carriers including T-Mobile USA and U.S. Cellular in getting the right to sell it. U.S. Cellular Corp. says it turned down the chance to sell the phone because it didn't want to spend a few hundred dollars per phone, as other carriers do, so customers can buy it at Apple's listed, subsidized price.
— CHEAPER IPHONES: This spring, several small, regional cellphone companies began selling the iPhone at prices that undercut the big carriers. For instance, a basic 4S model was priced at $150 through those carriers, $49 less than what national carriers charge. Carriers making this cheaper offering include NTelos Wireless of Virginia; Appalachian Wireless of Kentucky; and Alaska Communications, Matanuska Telephone Association and GCI of Alaska.
— NO CONTRACTS: Leap Wireless International Inc., the parent of the Cricket cellphone service, and Open Mobile, which serves Puerto Rico, started selling the latest iPhone models on a prepaid, no-contract basis this year.
— MORE NOW, LESS LATER: Virgin Mobile USA, one of Sprint's brands for prepaid, no-contract phone service, started selling the iPhone in June. It costs $549 for a basic model, higher than the $100 charged for Sprint-branded service. However, service will cost $30 a month and won't require a contract. Sprint charges $80 per month and requires a two-year contract. The Virgin Mobile customer can save nearly $800 over two years.
— LEFTOVERS: T-Mobile doesn't sell iPhones, but it's trying to lure AT&T iPhone owners who are out of contract to switch to T-Mobile. That had been possible, but iPhones had slower speeds on T-Mobile's networks. T-Mobile has reshuffled the frequencies on its network to let it match or even exceed AT&T's data speeds on iPhones. Initially, that will be noticeable only in a few spots scattered around in such cities as New York, Seattle, Las Vegas and Washington.