T-Mobile has wanted to shut down Sprint's legacy 3G CDMA network for quite a while now. The carrier first set January 1, 2022, as the deadline but had to push back the date by three months to March 31, 2022, following delays by one of its partners in transitioning customers out of the network. With the revised deadline now just a day away, T-Mobile has silently delayed the sunset of the cell service by an additional two months to May 31, 2022.

While the carrier has yet to announce this delay, the revised date has been updated on SoftBank's website (via T-Mo Report) related to Sprint's CDMA network shutdown. That's not it, though; the update even notes that "there's a possibility that the date of May 31 will be rescheduled in future."

T-Mobile has also sent emails to some Sprint customers still using a CDMA phone informing them of the new timeline. While the final date of pulling the plug on the legacy network will be May 31, the report states that T-Mobile will start the phaseout process from March 31. The process will happen in waves over the next couple of months, transitioning business customers first. Seemingly, the CDMA lines will be disabled, and calls will be redirected to customer care.

Apart from the CDMA network, T-Mobile is also working on shutting down Sprint's LTE network and its own 3G/UMTS cell service. However, these shutdowns have also seen their fair share of delays. Sprint's cellular LTE service is now scheduled to be sunset on June 30, 2022. As for T-Mobile's 3G/UMTS coverage, its initial shut down date of October 1, 2021, was pushed back by almost a year to July 1, 2022. The carrier is doing away with old network technologies to free up spectrum for modern devices and reduce infrastructure costs.