What changed in ARRAY DIGITAL INFRASTRUCTURE, INC.'s 10-K — 2024 vs 2025

Item 1. Business General On August 1, 2025, United States Cellular Corporation changed its name to Array Digital Infrastructure, Inc. (Array). Array is used throughout this report even when referring to historical periods. On August 12, 2025, the Array Common Shares ticker symbol on the New York Stock Exchange changed to "AD".

Array connects America through digital infrastructure by leasing tower space to tenants and providing ancillary services. As of December 31, 2025 , Array owns 4,450 towers in 19 states. Array also holds noncontrolling interests in primarily wireless operating companies and holds certain wireless spectrum licenses.

As of December 31, 2025, Array is an 82.0%-owned subsidiary of Telephone and Data Systems, Inc. (TDS). Through July 31, 2025, Array provided wireless communication services; these operations and certain wireless spectrum licenses were disposed of on August 1, 2025, as discussed further below.

Operating Strategy and Recent Developments Array is the fifth largest tower owner and operator of shared wireless communications infrastructure in the United States. With 4,450 cell towers, Array enables the deployment of 5G and other wireless technologies throughout the country. Array has a unique wireless carrier heritage and has owned and operated towers for over 40 years.

This experience gives Array a robust understanding of the needs of its wireless customers and enables the delivery of exceptional service. Array has built a strong and focused organization that has been and will be relied upon as an efficient and cost-effective partner for colocation.

Array’s strategy is to drive increased colocation on its portfolio of unique tower locations and support the delivery of connectivity to the communities in which it operates. Array’s operations are characterized by: • Array’s tenants lease space on Array's communications infrastructure, installing network equipment on Array tower structures.

Revenues vary by tenant and are dependent on numerous factors, such as quantity of installed equipment, location of installed equipment on the tower structure and tower location, amongst others. Array has entered into long-term Master License Agreements (MLAs) with its largest customers, which ensures a defined lease term and defined lease escalators.

Array generally experiences very limited tenant churn and high lease renewal rates driven by the high cost tenants incur to move sites as well as the potential lack of availability of suitable alternative tower structures.

Array's largest tenants include T-Mobile, AT&T and Verizon. • Array's towers are generally located on leased land, though approximately 18% of the portfolio is located on deeded land or land where there is a perpetual easement. Additionally, over 65% of towers on leased land have a lease expiration date ten years or more in the future.

Array's towers generally sit within a fenced compound that contains the tower itself as well as space for tenant equipment including shelters and generators. The average height of an Array tower is 260 feet, with tower heights ranging from 60 to 600 feet. Array's portfolio consists of monopole, self-support (lattice), and guyed towers.

In addition to the tower structure, guyed towers have guy-wires that extend down to guy anchors. Substantially all of Array's towers have adequate tower capacity and ground space to accommodate additional tenants. • Demand for tower infrastructure continues to be high, driven primarily by continued growth in mobile data consumption.

Array is in a unique position of having a lower tenancy rate than other tower operators due to the tower portfolio being part of the broader legacy wireless business prior to August 2025.

This provides Array with ample remaining leasable vertical real estate in attractive rural, suburban and urban areas in the communities in which Array operates. • Array's direct tower operations costs consist of ground rent, tower maintenance, utilities, property tax and property insurance.

Ground rent is the largest of these operating costs and is generally governed by long-term ground lease agreements with periodic escalators. • Array’s Selling, general and administrative expenses include employee related expenses, bad debts expense, consulting fees, and other general and administrative expenses.

In 2025, Selling, general and administrative expenses also included significant costs associated with the wind down of the wireless operations that were not included in discontinued operations. These expenses are expected to persist at a declining rate into future periods.

Array’s strategy is focused on: • T-Mobile MLA integration: Continued partnership with T-Mobile to implement the provisions of the long-term MLA.

This includes the execution of the 2,015 committed site lease agreements (SLAs), caring for interim site terminations, and partnering to drive incremental tenancies above the MLA commitment. 1 Table of Contents • Growing colocation revenue: Array is focused on increasing the cash flow generated from its tower portfolio and is positioned to drive growth over the coming years.

First, over one-third of Array's portfolio of towers has no competing structure within a two-mile radius. Second, Array's tenancy rate is lower than other tower companies, providing sufficient capacity for additional tenants and greater opportunity for lease up.

Third, Array has a dedicated sales team supporting its carrier customers and has recently added dedicated team members to support its non-carrier customers and continue to grow those relationships.

From an industry perspective, Array believes that continued growth in demand for wireless services, spectrum build-outs, efforts to bridge the digital divide and the emergence of next-generation technologies will drive the need for additional communications infrastructure. • Ground lease optimization: Array seeks to increase its ground ownership position through continued ground lease purchases as well as proactively renewing ground leases well before lease expiration. • Evaluation of towers without tenants portfolio: At the conclusion of the T-Mobile integration, Array expects to have 800 – 1,800 towers without tenants.

Ongoing analysis will inform Array's strategy for these towers, including assessing the leasability of each tower, ground rent rationalization and long-term alternatives.

Array believes that on balance there is significant value in its towers without tenants portfolio that it will strive to unlock through a combination of activities, including increased leasing, ground rent rationalization, and if necessary, divesting, including potential decommissioning, for these locations. On August 1, 2025, Array sold its wireless operations and select spectrum assets to T-Mobile US, Inc.

(T-Mobile) under a Securities Purchase Agreement (Securities Purchase Agreement). Total consideration received was $4,293.8 million after adjustments which included a combination of $2,628.8 million in cash proceeds and $1,665.0 million in debt assumed by T-Mobile through the preliminary results of an exchange offer made to Array's debtholders, which subsequently closed on August 5, 2025.

The final cash proceeds are subject to adjustment according to the terms and conditions of the Securities Purchase Agreement. At closing, a $16.7 million deferral of the purchase price was recorded related to certain spectrum licenses included in the transaction that did not transfer to T-Mobile and are subject to FCC approval.

Further, at closing, Array and T-Mobile entered into a Master License Agreement (MLA), pursuant to which, among other things, T-Mobile has agreed to license from Array space on towers owned by Array. The wireless operations and select spectrum assets sold to T-Mobile are presented as discontinued operations throughout this report.

See Note 2 — Discontinued Operations in Notes to Consolidated Financial Statements for additional information. In addition to the sale of Array's wireless operations and select spectrum assets sold to T-Mobile pursuant to the Securities Purchase Agreement, Array also separately entered into the following agreements to sell spectrum license assets.

Spectrum Licenses Buyer Purchase Price Book Value as of December 31, 2025 Signing Date Estimated or Actual Close Date (Dollars in thousands) AWS, Cellular and PCS 1 Verizon $ 1,000,000 $ 585,579 October 17, 2024 Q2/Q3 2026 3.45 GHz and 700 MHz AT&T $ 1,018,044 $ 860,145 November 6, 2024 January 13, 2026 700 MHz 1 T-Mobile $ 85,000 $ 64,267 August 29, 2025 2026 600 MHz 1 T-Mobile $ 86,387 $ 86,454 October 7, 2025 2026 1 These license transactions remain subject to regulatory approval and other customary closing conditions, and in the case of the sale to Verizon, the termination of the T-Mobile Short-Term Spectrum Manager Lease Agreement.

This includes, but is not limited to, large tower operators (American Tower Corporation, Crown Castle Inc and SBA Communications Corporation), regional tower operators, build-to-suit tower providers, owners of non-tower infrastructure that can be leveraged to house communications equipment (e.g., rooftops) and wireless providers that opt to own and operate their own infrastructure.

The primary competitive factors in the industry include tower location, speed of deployment and lease agreement structure (pricing and entitlements), as well as expertise in the end-to-end leasing process. 2 Table of Contents Regulation Array's operations are subject to federal, state and local regulation, including Federal Communications Commission (FCC) and Federal Aviation Administration (FAA) regulation.

The FCC and FAA regulate towers for wireless communications, radio, or television broadcasting. These regulations dictate the registration, lighting, marking and maintenance of Array's towers as well as siting and construction of any new towers and are dependent on such factors as the height of the tower and the proximity to an airfield.

New tower construction and some modifications to existing structures are also subject to the National Environmental Policy Act (“NEPA”), National Historic Preservation Act (NHPA) and/or other federal, state and local regulations. Array is subject to state and local regulations around land use, subdivision and zoning restrictions and restrictive covenants imposed by local authorities and developers.

These regulations vary but can require approval from local authorities, community organizations or environmental organizations before tower construction or modifications to an existing tower. At times these bodies can block tower construction or modification, impeding Array’s ability to meet customer demand.

As an owner and operator of real estate, Array is subject to federal, state and local environmental and hazardous materials regulation. Human Capital Resources Company and Culture Array had approximately 60 full-time and part-time associates as of December 31, 2025.

Array provides a competitive wage and benefits package, a safe workplace, and an environment where associates feel engaged and a sense of belonging. Array periodically surveys its associates to understand the level of associate engagement and overall job satisfaction.

Development and Leader Effectiveness Array is committed to advancing associate development and leadership effectiveness, recognizing these are essential to long-term success. All associates receive job-specific, safety, security, and fraud awareness training, supported by programs that promote continuous growth, including educational assistance, developmental assignments, and mentoring opportunities.