28 Apr 2025 U.S. Fiber Lit Buildings LEADERBOARD
AT&T ranks #1 on U.S. Business Fiber LEADERBOARD for tenth year; Fiber Lit Buildings approach 2 million sites
BOSTON, MA, April 28, 2026 – Vertical Systems Group’s 2025 U.S. Fiber Lit Buildings LEADERBOARD results are as follows (in rank order by number of on-net fiber lit buildings): AT&T, Verizon, Spectrum Business, Comcast Business, Lumen, Cox Business, Zayo, Crown Castle, Frontier, Uniti, Breezeline, Brightspeed and Segra. These thirteen retail and wholesale fiber providers qualify for the year-end 2025 benchmark based on a threshold of 25,000 or more on-net U.S. fiber lit sites, including commercial buildings and Data Centers.
Seven companies attain a 2025 Challenge Tier citation as follows (in alphabetical order): Altafiber, Conterra Networks, Everstream, Fidium, FirstLight, Great Plains Communications, and Lightpath. Each of these providers qualifies for the 2025 Challenge Tier with between 5,000 and 24,999 U.S. fiber lit commercial sites.
“U.S. installations of commercial fiber circuits and lit buildings increased in 2025 as providers focused on higher speed offerings. Top fiber providers are actively expanding buildouts to meet demand for lower latency, higher bandwidth edge computing applications driven by AI,” said Rosemary Cochran, principal of Vertical Systems Group. “The number of lit fiber buildings increased across every building size segment during the past year. Currently greater than 80% of large and medium size buildings are fiber lit.”
U.S. Fiber Lit Buildings LEADERBOARD Highlights
- AT&T retains the top rank on the 2025 U.S. Fiber Lit Buildings LEADERBOARD for the tenth consecutive year. During this time period the company has steadily expanded its installed base of fiber lit buildings across the U.S.
- The 2025 LEADERBOARD expanded to thirteen companies that have achieved the threshold of 25,000 or more fiber lit buildings.
- LEADERBOARD rankings for the top nine providers remain unchanged.
- Three fiber providers advance to the LEADERBOARD from the Challenge Tier: Uniti (including Windstream), Brightspeed and Segra (including UPN).
- In 2025 the installed base of fiber lit commercial buildings and Data Centers reached nearly two million sites.
- A number of LEADERBOARD providers have already completed or are planning mergers that will be reflected in our next analysis. In 2026 AT&T acquired Lumen’s Mass Markets fiber business and Verizon acquired Frontier. Expected to close in 2026 are the Charter/Cox merger and Zayo’s acquisition of Crown Castle’s fiber solutions assets.
- Ciena, Cisco, Fujitsu and Nokia are the top technology suppliers to U.S. fiber providers.
Market Players include all other fiber providers with fewer than 5,000 U.S. commercial fiber lit buildings. The 2025 Market Players tier covers more than two hundred metro, regional and other fiber providers, including the following companies (in alphabetical order): ACD, Alaska Communications, American Telesis, Arelion, Armstrong Business Solutions, Astound Business, Bluebird Fiber, C Spire, Centracom, Cogent, DFN, DQE Communications, Exa Infrastructure, ExteNet Systems, Fatbeam, FiberLight, First Digital, Flo Networks, Fusion Connect, GCI Liberty, GCX, Glo Fiber, Google Fiber, Hunter Communications, Logix Fiber Networks, LS Networks, Mediacom Business, MetroNet Commercial, Midco, PS Lightwave, Ritter Communications, Silver Star Telecom, Sonic Business, Sparklight Business, Syringa, T-Mobile Fiber, Tata Communications, TDS Telecom, U.S. Signal, Vast Networks, WOW!Business, Ziply Fiber, and others.
For this analysis, a fiber lit building is defined as a commercial site or data center that has on-net optical fiber connectivity to a network provider’s infrastructure, plus active service termination equipment onsite. Excluded from this analysis are standalone cell towers, small cells not located in fiber lit buildings, near net buildings, buildings classified as coiled at curb or coiled in building, HFC-connected buildings, carrier central offices, residential buildings, and private or dark fiber installations.
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