Late last year, AT&T confirmed it would be eliminating two-year service agreements in the New Year. The nation's second largest wireless provider made good on that promise Friday in the midst of CES, leaving fourth-place Sprint as the only major carrier still pushing subsidized smartphones.

If a leaked internal document obtained by Android Central is legit, however, Sprint has just done away with smartphone contracts as well.

A screenshot of the document says customers activating a new account no longer have the option to purchase phones using two-year contracts to take advantage of device subsidies. Tablets are apparently still fair game, however. Subsidy agreements for phones can now only be offered on a reactive basis to select customers.

A quick check of Sprint's website reveals that phones can only be purchased via payment plans or by paying in full. What's more, Fierce Wireless said Sprint CFO Tarek Robbiati all but confirmed the move during an investor conference yesterday.

T-Mobile eliminated phone subsidies in early 2013, a decision that set in motion a complete transformation of the wireless industry. Rather than have to wait two years to get a new phone, consumers are now free to upgrade handsets multiple times a year through various early upgrade and leasing programs.