Data / Federal rules / 2026-15598

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

The Federal Communications Commission published this final rule in the Federal Register on July 31, 2026. It took effect on September 29, 2026.

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What the agency says

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.

Key facts

Document number

2026-15598

Type

Final rule

Action

Final rule

Agency

Federal Communications Commission

Published

July 31, 2026

Takes effect

September 29, 2026

Dates

The rules are effective September 29, 2026, except for instruction 7 (Sec. Sec. 25.138(a) and (b)); instruction 8 (Sec. 25.147); instruction 17 Sec. (27.14(x)(3)); instruction 26 (Sec. 27.1412(b), (c), (e), and (g); instruction 28 (Sec. 27.1413(a)(3), (c)(1), (c)(9), (e) and (f)); instruction 30 (Sec. 27.1414(e)); instruction 31 (Sec. 27.1415); instruction 32 (Sec. 27.1416); instruction 33 (Sec. 27.1417); instruction 35 (Sec. 27.1419); instruction 37 (Sec. 27.1421); instruction 39 (Sec. 27.1422(c)); and instruction 41 Sec. 27.1424 of the Commission's rules, which contain new or modified inform

Docket

GN Docket Nos. 18-122 and 25-59; FCC 26-46; FR ID 359523

Code of Federal Regulations

47 CFR 1; 47 CFR 25; 47 CFR 27

Topics

Administrative practice and procedure; Communications; Communications common carriers; Radio; Reporting and recordkeeping requirements; Satellites; Telecommunications

Pages

51

The document on federalregister.gov PDF

Other documents from the Federal Communications Commission

Everything from the Federal Communications Commission · Rules on administrative practice and procedure · Rules on communications · Rules on communications common carriers · Published in July 2026

Read from the Federal Register API, last updated 2026-10-23. The document on federalregister.gov is the official record; dates and dockets can change through later corrections. Free to reuse with credit to SpecStream under CC BY 4.0.