Why is T-Mobile Fiber not working? T-Mobile's home internet service buckled under a sweeping outage today, May 28, 2026, leaving thousands of T-Mobile fiber customers completely offline. The T-Mobile fiber outage struck in the early hours of the morning, with spike reports beginning around 1 AM ET and swelling past 1,000 complaints on Downdetector by mid-morning. For many households, this wasn't just a slow connection — it was total darkness, and that distinction matters.
What makes today's T-Mobile fiber outage especially frustrating is the context behind it. T-Fiber, formerly Lumos Fiber, only recently transitioned into T-Mobile's brand after the company's $950 million joint-venture investment in early 2025.
