47 CFR §27.1508
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
The predicted or measured median field strength must not exceed 40 dBµV/m at any given point along the geographic license boundary, unless the affected licensee agrees to a different field strength. This value applies to both the initially offered service areas and to partitioned service areas.