C-band
C-band is the 3.7–3.98 GHz mid-band 5G frequency that Verizon and AT&T paid $80B+ for in 2021. It's the most consequential 5G deployment in the US — fast and reasonably wide-reaching.
C-band refers to the 3.7–3.98 GHz mid-band 5G frequency range. It's the spectrum Verizon and AT&T paid more than $80 billion combined for in the FCC's Auction 107 in 2021. C-band is the technical reason the US 5G experience improved dramatically between 2022 and 2024 — before C-band, Verizon's 5G was largely the slow low-band variety; after, the 5G-on-the-icon experience started actually being fast.
How C-band performs
Speeds in real-world conditions: 200–700 Mbps download in good coverage, with 100–300 Mbps consistent at the cell edge. Reach: about a mile from the tower in line-of-sight, less through buildings. C-band penetrates indoors better than mmWave but worse than low-band — concrete buildings often see significant signal loss; wood-frame homes barely notice.
Where C-band is deployed
Verizon began turning on C-band in early 2022 and has expanded coverage to most major US metros and many smaller cities by 2026. AT&T deployed slower but is now in similar shape. T-Mobile chose to skip C-band auctions because they already had 2.5 GHz mid-band (n41) from the Sprint merger; their 5G UC label refers to that band rather than C-band.
Why it matters for plan choice
If you're shopping for a Verizon-network plan (Verizon postpaid, Visible, Spectrum Mobile, Xfinity Mobile, Cox Mobile), the question of "do you get C-band coverage at your address" determines whether you get fast-5G or slow-5G. Coverage maps from those carriers show C-band as a separate overlay. Some MVNOs deprioritize C-band traffic during congestion more aggressively than postpaid Verizon — read the fine print if you're a stadium-goer.