Final rule · 2026-15598

Upper C-Band (3.98-4.2 GHz); Expanding Flexible Use of the 3.7 to 4.2 GHz Band

In this document, the Federal Communications Commission (Commission) adopted a Report and Order, Order of Proposed Modification, and Order on Reconsideration (Order), that expands the ecosystem for next-generation wireless services in the 3.7-4.2 GHz band (C-band) by making 160 megahertz of the 3.98-4.2 GHz band (Upper C- band) available for terrestrial wireless flexible use. This action is pursuant to Congress' direction in the One Big Beautiful Bill Act to complete a system of competitive bidding by July 4, 2027, for at least 100 megahertz of spectrum in the 3.98-4.2 GHz band. The Order creates a single 3.7 GHz Service that spans 3.7-4.14 GHz and adopts competitive bidding procedures for an auction. The Order largely applies the current Lower C-band licensing and operating rules to the Upper C-band, but it imposes more forward-leaning performance requirements. The Commission also generally adopts the Lower C-band technical rules for the Upper C-band, with certain modifications designed to reinforce a successful coexistence environment with adjacent band radio altimeters. The Order requires new licensees in the Upper C-band, as a condition of their licenses, to reimburse defined incumbent Fixed Satellite Service (FSS) licensees for reasonable and necessary costs associated with migrating FSS operations out of the reconfigured portion of the Upper C-band, consistent with the Commission's Emerging Technologies precedent. The Order also provides incentives to eligible space station operators that meet their clearing obligations by specified transition deadlines. Finally, new Upper C-band licensees must provide rebates for defined classes of eligible aircraft owners and operators to facilitate compliance with the FAA's radio altimeter retrofit requirements, which are designed to promote successful coexistence between Upper C-band licensees and radio altimeters in the 4.2-4.4 GHz band.