Reminder: RDOF Fabric Challenges to Correct Final Location Totals Are Due Sept. 1

The September 1, 2026, Fabric challenge deadline is quickly approaching. Rural Digital Opportunity Fund (RDOF) recipients must file any necessary challenges by that date for the challenges to be considered for inclusion in the December 2026 Broadband Serviceable Location Fabric (Fabric), which the Federal Communications Commission (FCC) will use to establish final adjusted RDOF location totals before recipients' sixth-year service milestones.

For recipients whose June 2026 Fabric data contains inaccurate location counts, missing or ineligible locations, incorrect unit counts, or other errors, the consequences of missing the September 1 deadline could be significant. The FCC has indicated that challenges not incorporated into the December 2026 Fabric will not be reflected in the data used to establish final RDOF location totals and deployment obligations. As a result, RDOF recipients could be required to deploy to locations that are ineligible or do not actually exist, encounter complications during the Universal Service Administrative Company (USAC) milestone verification process, have support recalculated based on inaccurate location totals, and ultimately face penalties or other enforcement consequences if they are unable to satisfy RDOF deployment milestones and obligations. This September 1 deadline therefore represents the last meaningful opportunity for recipients to correct the underlying Fabric data to accurately reflect conditions on the ground before their RDOF obligations are finalized.

Why This Deadline Matters

The FCC will use the December 2026 Fabric to establish final adjusted RDOF location totals before the sixth-year service milestones must be satisfied, consistent with the location-adjustment framework established in the original RDOF Order. Once the final location lists are adopted, RDOF deployment obligations will transition from an area-based approach to serving the specific Fabric locations identified on those lists, subject to limited exceptions.

Because the FCC and USAC transitioned to Fabric-based location lists for High Cost Universal Broadband (HUBB) reporting and service-milestone compliance, recipients can only add locations with Fabric IDs to the HUBB portal. Inaccurate Fabric data could affect a recipient's final deployment obligations, milestone compliance, and ability to receive credit for completed deployments. Such discrepancies could also complicate USAC's verification of interim and final deployment milestones, which requires recipients to demonstrate that reported locations are eligible and that the submitted coordinates correspond to the specific structures served.

The financial consequences of any discrepancies may affect the RDOF recipient's total support and will depend on whether the adjusted location total is above or below the recipient's original model-estimated total:

• Adjusted location total is at least 65% of the original model-estimated total: If the adjusted total is lower than the original model estimate but remains at least 65% of that estimate, there will be no change in support.
• Adjusted location total is less than 65% of the original model-estimated total: If the adjusted total falls below 65% of the original model estimate, support will be reduced on a pro rata basis for locations below that threshold.
• Adjusted location total exceeds the original model-estimated total: If the adjusted total exceeds the original model estimate, the provider generally must serve the original model-estimated total by the sixth-year milestone and the additional locations by the eighth-year milestone; however, additional support is available only for locations exceeding 135% of the original model-estimated total.

What RDOF Recipients Should Do Now

RDOF recipients should reconcile the June 2026 Fabric against their own location, engineering, and deployment data and determine whether any discrepancy requires a Fabric challenge or an internal data correction.

At a minimum, recipients should review the Fabric for:

• Missing broadband-serviceable locations;
• Locations that are abandoned, nonexistent, ineligible for RDOF support, or otherwise should not be treated as broadband serviceable;
• Secondary structures incorrectly identified as separate broadband-serviceable locations;
• Incorrect primary or secondary addresses;
• Missing or improper secondary addresses associated with multi-unit buildings;
• Incorrect residential or business unit counts;
• Incorrect building classifications or broadband-serviceable location designations;
• Duplicate or misplaced locations;
• Location points assigned to the wrong structure on a property or parcel; and
• Locations that do not align with engineering, deployment, GIS, or field records.

Recipients should preserve the records supporting their conclusions, including GIS data, engineering records, field documentation, service-availability information, unit-count support, and copies of submitted challenges. These materials will be important during USAC milestone verification, or if the provider seeks FCC relief relating to a service milestone.

Addressing Interim Milestone Shortfalls

Reviewing and challenging Fabric data is particularly important for RDOF recipients whose actual broadband-serviceable location counts differ from the model-estimated totals used to establish their obligations. Although the FCC will ultimately adjust deployment obligations based on Fabric data, upcoming interim milestones remain tied to the original model-estimated location totals.

The interim 40%, 60%, and 80% deployment benchmarks will continue to be measured against each provider's original model-estimated location total rather than its current Fabric count. A provider that has served every actual location in its RDOF territory but remains short of an interim milestone may ask USAC to verify its deployment against the June or December 2026 Fabric, whichever is more recent.

For recipients seeking verification that they have served 100% of the actual locations in their RDOF service areas before final deployment obligations are established, USAC will not initiate verification based on the June 2026 Fabric unless the provider has challenged ineligible locations. USAC will confirm 100% deployment only after those challenges are resolved in the provider's favor, at which point the provider must then seek an FCC waiver of the applicable interim milestone and continue monitoring the Fabric and deploying to additional locations until the end of the six-year milestone and applicable cure period.

Fabric challenges are therefore particularly important for recipients whose Fabric data identifies more locations than exist within their RDOF service areas.

Obligations for Additional Fabric Locations

If the final adjusted location total exceeds the provider's original model estimate, the provider generally will have until the end of the eighth calendar year to serve the additional locations. Additional support is only available for locations exceeding 135% of the original model-estimated total.

A provider may seek to exclude an additional location that is ineligible or unreasonable to serve. Ineligible locations must first be removed through the Fabric challenge process. For locations that remain in the Fabric, a provider may request an exclusion by demonstrating that the location is unreasonable to serve. The FCC has indicated that these requests will be evaluated on a case-by-case basis under a rigorous standard and are not expected to be granted routinely. Relevant considerations may include access restrictions, distance from the provider's existing network, terrain, deployment costs relative to anticipated revenues, and the provider's pre-auction due diligence.

The FCC expects to open the unreasonable-to-serve submission process when it adopts the final RDOF location lists and has indicated that it will provide additional information regarding the process at that time. Eligible recipients will then have six months to submit location-specific requests and supporting evidence.

Key Dates for RDOF Recipient Deployment Deadlines

• September 1, 2026: Deadline for Fabric challenges to be considered for inclusion in the December 2026 Fabric.
• December 31, 2026: Interim deployment milestone deadline based on original estimated location totals—80% for recipients authorized in 2021 and 60% for recipients authorized in 2022 or 2023.
• January 2027: The FCC expects to publish updated RDOF location lists based on the December 2026 Fabric, and USAC expects to update the HUBB portal to reflect those lists.
• March 1, 2027: HUBB reporting deadline and deadline for RDOF recipients to notify the FCC of actual locations that are less than model-estimated milestone locations.
• Spring 2027: FCC expects to adopt the final RDOF location lists, adjusted location totals, and any associated support adjustments. The submission window for eligible unreasonable-to-serve location requests is also expected to open in spring 2027.

The Takeaway: Review and Challenge Now

With the September 1 deadline approaching quickly, RDOF recipients should reconcile the June 2026 Fabric against their own engineering, deployment, and location records and file supported challenges for any inaccuracies. This is recipients' last meaningful opportunity to influence their final RDOF deployment obligations before the FCC establishes adjusted location totals based on the December 2026 Fabric. Recipients that fail to review and correct Fabric data may face increased compliance risks, including being required to deploy to locations that are ineligible or do not exist, complications during milestone verification reviews, impacts on support, and potential enforcement consequences if deployment obligations are not satisfied.

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Kasey McGee is an associate in DWT's Washington, D.C., office. K.C. Halm is a partner, co-chair of DWT's technology, communications, privacy & security practice, and chair of the firm's communications practice, also located in our Washington, D.C., office. For questions or more insights, please reach out to the authors or another member of our communications team and sign up for our alerts.