47 C.F.R. § 27.1412

(a) Transition deadlines. Eligible space station operators are responsible for all necessary actions to clear their transponders from the 4000-4160 MHz band and to migrate the existing services of incumbent earth stations in CONUS out of the 4000-4160 MHz band (unless the incumbent earth station opts out of the formal relocation process, per paragraph (f) of this section), in Partial Economic Areas 1-41 and 43-76 as of the Primary Transition Deadline, which is December 30, 2030. Terrestrial wireless operations may commence in the Partial Economic Areas subject to the Primary Transition Deadline as of December 31, 2030. For Partial Economic Areas 77-211, 213-263, 265-297, 299-359, and 361-411, the relevant transition deadline for eligible space station operators to clear their transponders from the 4000-4160 MHz band and to migrate the existing services of incumbent earth stations in CONUS out of the 4000-4160 MHz band (unless the incumbent earth station opts out of the formal relocation process, per paragraph (f) of this section) is the Final Transition Deadline, which is June 30, 2031. Terrestrial wireless operations may commence in the Partial Economic Areas subject to the Final Transition Deadline as of July 1, 2031, or as of the date that all eligible space station operators have had Certifications of Completion for the Final Transition Deadline validated and related incentive payments are made by the 3.7 GHz Service licensees in the 3980-4140 MHz band, whichever is sooner. Eligible space station operators that fail to clear by the Final Transition Deadline will be in violation of the conditions of their license authorization and potentially subject to forfeitures and other sanctions.

(b)-(c) [Reserved]

(d) Responsibility for meeting Transition Deadlines. An eligible space station operator's satisfaction of the relevant Transition Deadline shall be determined on an individual basis.

(e) [Reserved]

(f) Incumbent earth station opt-out. An incumbent earth station within the contiguous United States may opt out of the formal relocation process and accept a lump sum payment equal to the average estimated, reasonable costs of transitioning existing FSS C-band service out of 4000-4160 MHz, as determined by the Wireless Telecommunications Bureau, in lieu of actual relocation costs. An incumbent earth station that accepts a lump sum payment is responsible for coordinating with the relevant space station operator(s) as necessary and performing all relocation actions on its own, including switching to a new distribution technology. An incumbent earth station that accepts a lump sum payment will not receive further reimbursement for any costs exceeding the lump sum payment.

(g) [Reserved]

(h) Delegated authority. The Wireless Telecommunications Bureau is delegated the role of providing clarifications or interpretations to eligible space station operators and other transition stakeholders of the Commission's orders for all aspects of the transition, overseeing the Upper C-band Clearinghouse and the FSS transition cost reimbursement program and radio altimeter rebates, and taking such measures as are necessary to ensure the timely and efficient transition of the Upper C-band.