Wireless carrier U.S. Cellular (NYSE:USM) will get Apple's (NASDAQ:AAPL) iPhone "later this year," the company has announced.

The company included the news in its first-quarter earnings report, adding that offering Apple products will further strengthen its device portfolio. U.S. Cellular says its smartphone penetration is at 43% of core market customers.

With 5.7 million total customers throughout 26 states at the end of the quarter, the addition of U.S. Cellular as an official iPhone carrier is a relatively smaller deal for Apple relative to the four largest nationwide domestic carriers that now offer Apple's devices.

U.S. Cellular's current device lineup primarily consists of Google Android, Microsoft Windows Phone, and older BlackBerry 7 devices.