T-Mobile has been transitioning CDMA customers to its GSM based network aggressively for more than a year. "Any MetroPCS customer using a CDMA handset in a migration market was eligible for our HSPA/LTE device Upgrade Program," said T-Mobile. "In order to take advantage of the new network, all customers need to do is bring their active phone to a participating MetroPCS store, choose a new phone, apply their trade-in credit toward that phone, and start using the new network right away."
Some MetroPCS customers will quality for upgrade credits between $32 and $299 depending on their existing CDMA handset. Customers who didn't pick up a new phone before June 21 will lose service entirely when MetroPCS shuts down the CDMA network. T-Mobile plans to re-use the CDMA spectrum to supplement its LTE 4G network.