T-Mobile has launched a new upgrade plan that lets you buy a smartphone on a monthly payment plan then swap it out for a new model up to three times per year.

It’s called M On Dem, goes into effect ne 28. To kickstart the plan, T-Mobile is temporarily offering a 16GB ione 6 for $15 per month when you trade in another smartphone.

thout the promotion, the costs are a little higher. The Galaxy S6, for example, will set you back $28.33 per month while the ione 6 us will cost $31.24 monthly over 24 months. During that time you can trade in the phone for a new model start the clock over again. 

The target is consumers who don’t want to pay full-price for a phone (or even $200 up front then higher monthly bills), but who want the ability to get whatever new model rolls out from Apple, Samsung, or others.

As always, T-Mobile CEO gere has plenty to say about the new effort.

The story behind the story: T-Mobile has been the most aggressive among the nation’s big four carriers at changing up how smartphone plans work. Its moves to eliminate contracts, offer unlimited music streaming, allow data rollover, ditch subsidies have paid off in millions of new subscribers. AT&T Verizon have been quick to copy some of these features, so it’s worth keeping an eye on your current carrier to see what their next move might be.