T-Mobile said Wednesday that its shutdown of Sprint’s 3G network is proceeding as planned, beginning on March 31st. As part of the shutdown process, the company said in a statement emailed to The Verge, it will migrate customers over the next 60 days “to ensure they are supported and not left without connectivity, and the network will be completely turned off by no later than May 31.”

Earlier reports suggested that the actual shutdown date was being pushed to May 31st, which would have been the second delay; originally, T-Mobile was going to phase out the network in January but said in October that it would extend the deadline to March 31st.

As one of the conditions of the T-Mobile / Sprint merger, which closed in 2020, Dish acquired Boost Mobile in July 2020 with the goal of Dish taking Sprint’s place as a fourth wireless carrier in the US. After T-Mobile announced it planned to shut down Sprint’s CDMA network, the two companies engaged in some back-and-forth criticisms of each other; Dish chairman Charlie Ergen compared T-Mobile to the Grinch; T-Mobile CEO Mike Sievert wrote in a blog post that Dish was “dragging their feet in getting their customers upgraded to the superior 4G/5G world.”

At stake is the impact the shutdown will have on Dish’s Boost Mobile customers. The Department of Justice told Dish Network and T-Mobile in a July 2021 letter that it had “grave concerns” about the shutdown of Sprint’s legacy network and urged the companies to take “all appropriate steps” to reduce the effect on customers who rely on the network.

When it announced the delay to the end of March, T-Mobile released a statement saying its “partners” had not followed through “on their responsibility to help their customers through this shift” and that it was “stepping up” on the customers’ behalf. That appeared to be a thinly-veiled reference to Dish Network, whose executive VP of external legislative affairs Jeff Blum told The Verge at the time that COVID-related issues and supply-chain shortages had slowed the customer upgrades. He said the March delay was an acknowledgment by T-Mobile that shutting down the CDMA network could have a negative impact on consumers who rely on it.

Update March 30th 2:33PM ET: Clarifies that the shutdown will begin March 31st and be turned off completely by May 31st.