T-Mobile's fastest internet plan yet comes with a surprising 10-year promise

Your internet provider wants you to think bigger is always better. T-Mobile is making that pitch with a new 5Gbps fiber plan, but the more intriguing number isn’t the speed. It’s the ten years the carrier says customers can keep paying the same base rate.

Starting November 3, T-Mobile Fiber 5 Gig costs $90 a month with AutoPay, plus taxes and fees. That’s cheaper than AT&T’s $125 standalone 5Gbps rate announced earlier this year, and even its $100 bundled price. T-Mobile doesn’t require a wireless subscription to qualify.

The plan promises symmetrical upload and download speeds, meaning there’s room for large cloud backups, video uploads, and packed households without uploads taking a back seat. It also includes unlimited data, a router, professional installation, and a mesh extender when needed, with no annual contract.

But the 10-year promise deserves a closer look. When T-Mobile launched its broader fiber service, it offered five-year price guarantees and a limited 10-year Founders Club promotion. But a shake-up earlier this year brought cheaper plans at the expense of those long-term protections. Now the decade-long guarantee is making a comeback, although only for customers willing to pay for the fastest tier.

T-Mobile is also dangling limited-time incentives across its lineup:

• Fiber 300 (300Mbps): $35/month, down from $45, saving customers $10 monthly.
• Fiber 1 Gig (1Gbps): $55/month, down from $60, plus one month free and a $100 virtual prepaid card.
• Fiber 2 Gig (2Gbps): $70/month, plus one month free and $300 in virtual prepaid cards.
• Fiber 5 Gig (5Gbps): $90/month, plus two months free and $300 in virtual prepaid cards, alongside the 10-year price guarantee.

All prices require AutoPay and exclude taxes and fees. Free months come as bill credits, while prepaid cards can take up to 14 weeks to arrive. The promotions begin November 3 in select locations, although T-Mobile hasn’t announced when they’ll end.

There is one speed bump in the sales pitch. Most households won’t come close to saturating a 5Gbps connection, and getting those speeds on a single device requires compatible networking hardware. A bigger bandwidth number won’t automatically improve gaming latency or everyday browsing.

So T-Mobile’s real challenge isn’t convincing people that five gigs sounds impressive. It’s convincing customers to pay an extra $20 a month over the 2 Gig plan, not necessarily for the additional speed, but for the peace of mind that comes with locking in their internet price for the next decade.