Looks like T-Mobile is no longer the only major U.S. carrier without the iPhone. T-Mobile just announced that it'll begin selling Apple's iPhone 5 on April 12, complete with a down payment price of $99.99 along with 24 monthly payments of $20 each. Pre-orders for the T-Mobile iPhone 5 will begin on April 5. Customers that'd prefer something a bit cheaper will also be able to pick up the iPhone 4S for $69.99 down and 24 monthly payments of $20 each, or the iPhone 4 for $14.99 down and 24 monthly payments of $15 each. T-Mobile says that the iPhone 4S and iPhone 4 will be available "in select markets," while the iPhone 5 will be available nationwide.

Unsurprisingly, the iPhone 5 will support T-Mobile's 4G LTE network, which is officially going live in seven cities today. The magenta carrier also noted that its version of the iPhone 5 will also work on its 1700MHz AWS and 1900MHz HSPA+ service when the user is outside of T-Mobile's LTE coverage. Finally, the iPhone 5 will support HD Voice for enhanced call quality, a feature that T-Mobile announced earlier this year.

Apple originally introduced the iPhone in 2007, and at that time, the device was only available to customers on AT&T. It took until early 2011 for the iPhone to officially make its way onto another U.S. carrier with the introduction of the Verizon iPhone 4, and then Sprint became the third major operator to launch Apple's smartphone with the arrival of the iPhone 4S later in 2011. Now T-Mobile has joined the club, meaning that the iPhone is now available on all four big U.S. carriers. Of course, T-Mobile customers have been bringing unlocked iPhones onto the magenta network for just about as long as the iPhone has been around, but the official launch of the iPhone on T-Mobile ought to make getting an iOS smartphone on T-Mo a bit easier for most folks. Will you be picking up an iPhone 5, 4S or 4 on T-Mobile once they hit shelves?

UPDATE: Apple has shared more information on the T-Mobile iPhone 5 with Phone Scoop. As I noted previously, the version of the iPhone 5 that will be sold by T-Mobile on April 12 features support for 42Mbps HSPA+ connectivity on the 1700MHz AWS band. T-Mobile's iPhone 5 will also feature the same model number (A1428) as the variant currently being sold by AT&T and Apple. However, the version currently being sold by AT&T and Apple will not work with T-Mobile's 1700MHz AWS HSPA+ service. Those models will be able to access T-Mobile's refarmed 21Mbps HSPA+ network on the 1900MHz band as well as T-Mobile's LTE on the 1700MHz band with a software update.

Via T-Mobile, Phone Scoop, TmoNews