# Federal Register 2026-21324 — effective 2026-10-19 — Upper C-Band (3.98-4.2 GHz); Expanding Flexible Use of the 3.7 to 4.2 GHz Band — Federal Communications Commission

For Federal Register 2026-21324, effective date is 2026-10-19; agency is Federal Communications Commission; published is 2026-10-19; cfr parts amended is 47 CFR 27; dates, as printed is Amendatory instructions 26 (47 CFR 27.1412(e)) and 35 (47 CFR 27.1419), published at 91 FR 48700, July 31, 2026, are effective on October 19, 2026, recorded from its source on 2026-10-19; source re-checked 2026-11-03.

- **FR document number:** 2026-21324 _(verified: appears in the quote below)_
- **Rule:** Upper C-Band (3.98-4.2 GHz); Expanding Flexible Use of the 3.7 to 4.2 GHz Band _(verified: appears in the quote below)_
- **Agency:** Federal Communications Commission _(verified: appears in the quote below)_
- **Effective date:** 2026-10-19 _(verified: appears in the quote below)_
- **DATES, as printed:** Amendatory instructions 26 (47 CFR 27.1412(e)) and 35 (47 CFR 27.1419), published at 91 FR 48700, July 31, 2026, are effective on October 19, 2026. _(verified: appears in the quote below)_
- **CFR parts amended:** 47 CFR 27 _(our reading, not quoted from the source)_
- **Published:** 2026-10-19 _(verified: appears in the quote below)_

## What the source says

> {"document_number":"2026-21324","title":"Upper C-Band (3.98-4.2 GHz); Expanding Flexible Use of the 3.7 to 4.2 GHz Band","agency_names":["Federal Communications Commission"],"effective_on":"2026-10-19","dates":"Amendatory instructions 26 (47 CFR 27.1412(e)) and 35 (47 CFR 27.1419), published at 91 FR 48700, July 31, 2026, are effective on October 19, 2026.","cfr_references":[{"chapter":null,"citation_url":null,"part":"27","title":47}],"publication_date":"2026-10-19","html_url":"https://www.federalregister.gov/documents/2026/10/19/2026-21324/upper-c-band-398-42-ghz-expanding-flexible-use-of-the-37-to-42-ghz-band"}

## Source

- https://www.federalregister.gov/api/v1/documents.json?per_page=1000&order=oldest&conditions%5Btype%5D%5B%5D=RULE&conditions%5Beffective_date%5D%5Bgte%5D=2026-08-31&conditions%5Beffective_date%5D%5Blte%5D=2026-12-31&fields%5B%5D=document_number&fields%5B%5D=title&fields%5B%5D=agency_names&fields%5B%5D=effective_on&fields%5B%5D=dates&fields%5B%5D=cfr_references&fields%5B%5D=publication_date&fields%5B%5D=html_url

Last verified: 2026-11-03. Review by: 2026-11-16.
Part of [Federal rules taking effect: every US final rule in the Federal Register, by effective date](https://referencesource.org/federal-rules-taking-effect/).