The iPhone 5 officially launched on AT&T, Sprint, and Verizon on September 21st, and then came to a number of regional carriers on September 28th. However, Sprint’s Virgin Mobile prepaid brand still isn’t offering the iPhone 5. They did begin to offer the iPhone 4S in June with prepaid plans starting at $30/month.
MacRumors has since confirmed that Virgin Mobile has CDMA iPhone 5′s ready for a launch. However, it is unknown when Virgin Mobile might begin offering the iPhone 5. In fact, only Virgin Mobile and Alaska Communications have yet to offer the new device amongst the regional carriers that Apple has partnered with here in the States.
If I had to guess, the lack of iPhone 5 on Virgin Mobile stems from the tight supplies due to high demand for the device. Apple is undoubtedly scrambling to meet demand, as more and more carriers begin offering the iPhone 5 as a part of the planned rollout.