The 4.5-inch LTE-enabled smartphone arrives in staggered launch dates throughout July.
The Un-carrier and its no-contract brand will carry an entry-level LG Optimus handset each, aimed at wallet-conscious customers.
Priced at $50, the LG Optimus L70 is one of the best 4G Android handsets on any prepaid network.
The carrier now offers the new S5 for the full contract-free price of $649.
The no-contract carrier adds Samsung's latest smartphone to its Android portfolio.
It's ahead of schedule in migrating customers from the MetroPCS and plans to decommission the old network in Boston, Philadelphia, and Las Vegas by the end of the year.
Available first on T-Mobile's network, these mid-and entry-level Android phones make the move to Metro.
The off-contract ZTE ZMax is equipped with an 8-megapixel camera, Android 4.4, and an expansive 5.7-inch LCD screen.
The prepaid carrier's latest is a 4G LTE Android that can withstand water, drops, and dust.
The offer, which is valid between Wednesday and November 3, is available to both new and existing customers.