The combination cell phone, media player and wireless Web device will only be sold at stores owned by Apple Inc. and AT&T Inc. (T), which has an exclusive deal to offer service for the device when it's launched June 29.
It will also be available at launch on Apple's Web site.
The device goes on sale at 6 p.m. local time in each U.S. market.
AT&T spokesman Fletcher Cook said the limited availability will only be for the initial launch. Later, it will be sold on AT&T's Web site and through other outlets.
AT&T owns 1,800 retail stores — which it has been rebranding from Cingular since taking over complete ownership late last year — but thousands of other franchise outlets carry the AT&T or Cingular name.
In all, AT&T has 8,000 franchise outlets and retail carriers, though retailers usually carry AT&T competitors as well.
Cook said the AT&T-owned stores are branded that way, whereas other franchise outlets still carry the Cingular name.
The iPhone will sell for $499 and $599, but AT&T has not disclosed what the contract service fees will be.
The device, which uses a touch-sensitive screen rather than a keypad, has been hotly anticipated with more than 1 million people signing up with AT&T to receive notice when the device is available.
Apple has not indicated how many units will be available at launch.