Trying to keep up with the latest offers from the big four wireless carriers is practically a full-time job as new promotions are seemingly rolled out on a daily basis. Such is the case here today as AT&T has added another tier to its Next smartphone purchasing program.

Next 24, announced during the AT&T Consumer Industry Analyst Conference, spreads the number of payments for a new smartphone over a total of 30 months which effectively lowers the amount due each month.

Under the new tier, subscribers can trade in their current smartphone after making 24 monthly payments (so long as it is in good condition) and upgrade to a new device. Conversely, buyers can pay off the remaining balance of their existing phone and keep it should they so choose.

Next 24 joins the company’s existing Next 18 and Next 12 tiers which divide payments into 24 or 20 equal payments, respectively. It’s a common misconception that the number associated with each tier represents the total number of payments due which simply isn’t the case. Instead, it indicates how many monthly payments must be made before you can trade in your device for another handset.

T-Mobile pioneered the concept of early upgrades with its Jump program last year, forcing the competition to follow suit.

Originally, these programs were a total rip-off as they essentially duped customers into paying full price for their phones – something that was typically subsidized by the carrier in exchange for signing a contract. Wireless providers like AT&T have since modified their offerings to offer a discount on service plans for those that utilize the programs.

With AT&T, for example, customers can save $15 per month if they subscribe to a Mobile Share Value plan with less than 10GB of data and $25 per month on plans with 10GB of data or higher.