Credit: Joe Maring / Android AuthorityTL;DRIn a statement shared with us, T-Mobile has confirmed it is retiring its oldest plans from the 3G and 4G eras and transitioning customers to modern plans.Some customers could see an increase in their monthly bill. All customers are promised that they will keep their current benefits.The company has not yet confirmed which plans are being retired, and which plans users are being moved to.Verizon’s new Simplicity plans were expected to be a catalyst for new plans from AT&T and T-Mobile, but it seems at least one of those carriers has different plans. T-Mobile has confirmed that it is retiring some of its oldest plans and migrating customers to newer plans.In a statement shared with us at Android Authority, a T-Mobile representative said the following: