ADTRAN Holdings, Inc. (ADTN) Business

ITEM 1. BUSINESS

Company Overview

ADTRAN Holdings, Inc. (“Adtran” or the “Company”) is a leading global provider of networking and communications platforms, software, systems and services focused on the metro optical transport, data center interconnect, and broadband access market, serving a diverse domestic and international customer base in multiple countries that includes large, medium and small Service Providers, alternative Service Providers, such as utilities, municipalities and fiber overbuilders, cable/MSOs, SMBs and distributed enterprises, including Fortune 500 companies with sophisticated business continuity applications; hyper-scalers, neocloud and content providers and data center companies; and federal, state and local government agencies.

We are focused on being a top global supplier of fiber-based communications infrastructure and AI-driven operations including SaaS applications spanning from the network core to the cloud edge (data centers) to the subscriber edge (customer premises) serving both the residential and enterprise connectivity markets, including fiber-based infrastructure for mobile networks. We offer a broad portfolio of flexible network infrastructure solutions, customer premises equipment, software applications, and global services and support that enable Service Providers to meet their service demands now and in the future. These products and services enable Service Providers to transition to a common network supporting the simplified delivery of high-capacity services, regardless of subscriber density, network topology and infrastructure diversity. We support our customers through our direct global sales organization and our distribution networks. Our success depends upon our ability to have customers adopt our technology, and increase unit volume and market share through the introduction of new products and succeeding generations of products having optimal selling prices and increased functionality as compared to both the prior generation of a product and to the products of competitors in order to gain market share. To service our customers and grow revenue, we are continually conducting research and developing new products addressing customer needs and testing those products for the specific requirements of the particular customers.

We solely own ADTRAN, Inc. and are the majority shareholder of Adtran Networks. ADTRAN, Inc. is a leading global provider of open, disaggregated networking and communications solutions. Adtran Networks is a global provider of network solutions for data, storage, voice and video services. We believe that the combined technology portfolio can best address current and future customer needs for high-speed connectivity from the network core to the end consumer, especially upon the convergence of solutions at the network edge.

We operate in two business segments: (1) Network Solutions, which includes hardware and software products, and (2) Services & Support, which includes a portfolio of network design and implementation services, support services and AI-driven operations including cloud-hosted SaaS applications that complement our product portfolio and can also be utilized to support other platforms. These two segments span across our three revenue categories: (1) Subscriber Solutions, (2) Access & Aggregation Solutions and (3) Optical Networking Solutions. See "Reportable Segments" below for a detailed discussion of these reportable segments and revenue categories.

We began operations in January 1986. Our global headquarters are located at Cummings Research Park in Huntsville, Alabama, the second largest research park in the U.S. and fourth largest in the world. Our European headquarters are located in Munich, Germany, and we have sales and research and development facilities in strategic global locations. Our mailing address is 901 Explorer Boulevard, Huntsville, Alabama, 35806. Our telephone number at that location is (800) 923-8726. Our website is www.adtran.com. The information found on our website is not incorporated by reference in this report or any other report that we file or furnish to the SEC.

Domination and Profit and Loss Transfer Agreement

The DPLTA between the Company, as the controlling company, and Adtran Networks, as the controlled company, was executed on December 1, 2022 in connection with the Company’s business combination with Adtran Networks, and became effective on January 16, 2023. Pursuant to the DPLTA, the Company has effective control over Adtran Networks subject to the terms of DPLTA. For more information on the DPLTA, see “Management’s Discussion and Analysis of Financial Condition and Results of Operations – Adtran Networks Domination and Profit and Loss Transfer Agreement” in Part II, Item 7 of this report.

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Reportable Segments

Our business operates two reportable segments: (1) Network Solutions and (2) Services & Support. We review our financial performance, specifically revenue and gross profit, based on these two segments.

Network Solutions Segment

The Network Solutions segment includes hardware and software products that enable a digital future which support the Company's Subscriber, Access and Aggregation, and Optical Networking Solutions. The Company's cloud-managed Wi-Fi gateways, virtualization software, and switches provide a mix of wired and wireless connectivity at the customer premises. In addition, its Carrier Ethernet products support a variety of applications at the network edge ranging from mobile backhaul to connecting enterprise customers (“Subscriber Solutions"). The Company's portfolio includes products for multi-gigabit service delivery over fiber or alternative media to homes and businesses.

Services & Support Segment

The Services & Support segment offers a comprehensive portfolio of network design, implementation, maintenance and cloud-hosted services supporting its Subscriber, Access & Aggregation, and Optical Networking Solutions. These services assist operators in the deployment of multi-vendor networks while reducing their cost to maintain these networks. The cloud-hosted services include a suite of SaaS applications under the Company's Mosaic One platform that manages end-to-end network and service optimization for both fiber access infrastructure and mesh Wi-Fi connectivity, featuring AI-driven operations. The Company backs these services with a global support organization that offers on-site and off-site support services with varying SLAs.

Revenue Categories

In addition to our two reportable segments, we also report revenue across three categories – Subscriber Solutions, Access & Aggregation Solutions and Optical Networking Solutions.

Our Subscriber Solutions portfolio is used by Service Providers to terminate their access services infrastructure at the customer's premises while providing an immersive and interactive experience for residential, business and wholesale subscribers. This revenue category includes hardware- and software-based products and services. These solutions include fiber termination solutions for residential, business and wholesale subscribers, Wi-Fi access solutions for residential and business subscribers, Ethernet switching and network edge virtualization solutions for business subscribers, and cloud software solutions covering a mix of subscriber types.

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The Subscriber Solutions category includes the following products, software and services:

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Our Access & Aggregation Solutions category represents solutions that are used by communications Service Providers to connect residential subscribers, business subscribers and mobile radio networks to the Service Providers’ metro network, primarily through fiber-based connectivity. This revenue category includes hardware- and software-based products and services. Our solutions within this category are a mix of fiber access and aggregation platforms, precision network synchronization and timing solutions, and access orchestration solutions that ensure highly reliable and efficient network performance.

The Access & Aggregation category includes the following products, software and services:

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Our Optical Networking Solutions are used by communications Service Providers, internet content providers and large-scale enterprises to securely interconnect metro and regional networks over fiber. This revenue category includes hardware- and software-based products and services. Our solutions within this category include open optical terminals, open line systems, optical subsystems and modules, network infrastructure assurance systems, and automation platforms that are used to build high-scale, secure and assured optical networks.

The Optical Networking Solutions category includes the following products, software and services:

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Industry Overview

The global growth of the cloud and mobility (5G), industrial applications, AI, home office and mobile working are accelerating the demand for more bandwidth, requiring more flexible provisioning of telecommunications services and more precise network synchronization. Communications Service Providers' investment in their networks is being driven by the pursuit of growth in subscriber acquisition, retention, and average revenue per user, as well as by the aims of streamlining operations, lowering energy consumption and improving their overall sustainability. Drivers facilitating this network investment cycle include the evolution of government funding programs, private equity infrastructure investment appetite, regulatory broadband policies, competition and ever-increasing subscriber demand for higher-speed broadband.

Subscriber demand for greater bandwidth continues to increase as connectivity is being woven ever more tightly into the fabric of everyone’s day-to-day lives. Specifically, subscriber demand for greater bandwidth is being driven by increasing numbers of connected devices, shifting working arrangements, the transition of entertainment over to OTT video, and the evolution of gaming platforms towards subscription models where new hybrids of download and streaming are emerging globally. This is further compounded by the rapid adoption of AI, the prevalence of IoT and the increasing transition of applications over to cloud-based services and internet applications where recurring revenues replace one-time sales. Performance and user satisfaction are directly related to bandwidth availability and service robustness. As the demand for high-definition video and game streaming services, symmetric bandwidth for online collaboration, lower latency for interactive AI and cloud applications and smart home video surveillance applications continue to increase, so too does the need increase for fiber-based broadband to be in every home and business.

In order to satisfy these complex requirements and deliver on the efficiency improvements demanded by operators, communications Service Providers are transitioning to full fiber access networks.

We aim to serve as a trusted partner to our customers. Working side-by-side with our customers, we assist them with maximizing the performance of their networks by providing a flexible path for their networks to evolve cost-effectively over to full fiber while availing themselves of the benefits that web-scale architectures deliver and helping to further monetize their investments.

Our Strategy

Our strategy is to provide innovative and cost-effective solutions for our customers that enable them to address their increasing broadband demand. Our solutions focus on technology transformations that are happening in broadband network infrastructure, home and business CPE and software platforms, and services needed to help our customers address increasing complexity while scaling to meet increasing consumer demands.

We aspire to be one of the top communication technology players in the world and an innovation leader around the converged edge, enabling the intelligent, self-optimizing, fiber-everywhere future. We plan to achieve this goal through innovation in network, home and business technology paired with a customer-focused organizational structure that tailors solutions to meet the needs of our target customers. We have one of the most comprehensive solutions portfolios that empowers operators to build a converged infrastructure from the metro core to the customer premise, serving all networking applications for residential, business, wholesale and mobile users. We take an approach to our portfolio in which we are focused in specific markets where we can offer competitive differentiation and scale while also having enough diversity and breadth in the portfolio to provide end-to-end connectivity solutions that offer value to our customers. More specifically, our corporate strategy consists of the following elements:

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Leadership in fiber networking: Breadth of portfolio, open and advanced architecture, assured and secure connectivity.

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Growth in focus markets: Increased turnkey solutions and in-region resources, especially North America and EMEA.

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Investment in converged edge: Innovation in optics, security, AI-driven networking, virtualization, SaaS, etc.

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Transformation through software: Open and cloud-centric systems, end-to-end programmability, simplification through software, and innovative SaaS offerings.

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Diversification of customers: Cross-selling current portfolio, acquisition of new customers and partners based on larger portfolio and trusted supplier status.

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Focus on sustainability: Science-based emissions targets, process-based product eco-design, optimization of operations, logistics and all packaging, circular-economy processes.

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Customers

We have a diverse global customer base that includes large, medium and small Service Providers, alternative Service Providers, such as utilities, municipalities and fiber overbuilders; cable/MSOs; SMBs and distributed enterprises.

During 2025, we had one customer who comprised greater than 10.0% of our revenue, which was an international Service Provider, and our next five largest customers comprised 20.4% of our revenue. Additionally, our revenue in the U.S., U.K. and Germany each comprised more than 10% of our revenue in 2025. The revenue from this Service Provider and these countries is reported in both our Network Solutions and Services & Support segments.

Distribution, Sales and Marketing

We sell our products through our direct sales organization and our distribution network. Our direct sales organization supports major accounts and has offices in global locations. Sales to most smaller and independent telecom companies are fulfilled through a combination of direct sales and distributors. Our service offerings can be purchased directly from us or through one of our Service Providers, channel partners or distribution partners.

Before placing an order, Service Providers typically require lengthy product qualification and standardization processes that can extend for several months or even years. Once approved, product orders are typically placed under single or multi-year supply agreements that are generally not subject to minimum volume commitments. Service Providers generally prefer having two or more suppliers for most products. Therefore, individual orders are usually subject to competitive combinations of total value, service, price, delivery and other terms.

Orders for end-user products are fulfilled through a combination of direct sales and distributors. This is supported by a direct sales organization for major accounts and a channel-based sales organization to facilitate sales to our partners. MSPs, VARs and SIs may be affiliated with us as channel partners, or they may purchase from a distributor in an unaffiliated fashion. Affiliated partners participate with us at various program levels, based on sales volume and other factors, to receive benefits such as product discounts, market development funds, technical support and training.

Outside of the U.S., most Service Provider products are sold through our direct sales organization and end-user products are sold direct or through distribution arrangements customized for each region. Some regions are supported from a field office that offers sales and support functions, and in some cases, warehousing and manufacturing support. Our field sales organizations, distributors and Service Provider customers receive support from regional-based marketing, sales and customer support groups.

Our marketing organization promotes all brands associated with us to key stakeholders, including customers, partners and prospects worldwide. Our product marketing and management teams work with our engineering teams to develop and promote new products and services, as well as product enhancements.

Research and Development

Rapidly changing technologies, evolving industry standards, changing customer requirements, supply constraints and continuing developments in communications service offerings characterize the markets for our products. Our on-going ability to adapt to these changes and to develop new and enhanced products that meet or anticipate market demand is the main factor influencing our competitive position and our ability to grow.

Our product development activities are a central part of our strategy. We plan to maintain our emphasis on product development to enable us to respond to rapidly changing technology and evolving industry standards. Our research and development and engineering functions are global. We maintain research and development functions at multiple sites in the U.S., Europe, Israel and Asia. During the years ended December 31, 2025, 2024 and 2023, research and development expenditures totaled $204.3 million, $221.5 million and $258.3 million, respectively.

While we develop the majority of our products internally, we also leverage partners for some solutions. Additionally, we license intellectual property or acquire technologies. Internal development on advanced technology products gives us more control over design and manufacturing issues, while for traditional designs, ODM and/or licensed intellectual property provides us with the ability to leverage the economies of scale of our technology partners.

As we continue to create more software-based intellectual property, such as our SDN/Edge Cloud portfolio, our use of lean agile practices in research and development ensures we remain responsive and customer-focused. We believe that this enables us to deliver products faster, at higher quality and more economically to our customers and the market on a continuous basis.

Our ability to continually reduce product costs, while focusing on delivery and quality, are important parts of our overall business strategy. Our product development efforts are often centered on entering a market with improved technology, which we believe enables us to offer products at competitive prices and compete for market share.

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Development activities focus on solutions that support both existing and emerging communications industry technologies in segments that we consider viable revenue opportunities. We are actively engaged in developing and refining technologies to support data, voice and video transport primarily over IP/Ethernet and optical network architectures. This includes optical transport, packet demarcation and aggregation, synchronization and fiber-optic access, DSL, access routing, ethernet switching, wireless LANs, integrated access, converged services, VoIP, network management and professional services. In addition, we focus on vertical optical technologies like Silicon Photonics, as well as microelectronics in order to differentiate and fully control the vertical value stack of our solutions. During 2025, we launched many new products, including an auto-tunable 50G C-band pluggable transceiver, expanded our Wi-Fi 7 portfolio with SDG 9000 Series for residential, small business and MDU connectivity, and launched the new FSP 3000 OLS solution. We also continued to advance our software and AI strategy through the Mosaic One platform.

Our research function and advanced technology team is driving many specific research projects in the fields of sustainable optical transmission, security, quantum communications, SDN and access technologies. This research fosters differentiated product concepts and guides our various product design and engineering teams in IPR creation, industry and network standards and technological forecasting.

We are an active participant in several SDOs and have assisted with the development of worldwide standards in many technologies. Our SDO activities are primarily in the areas of broadband access, optical networking and synchronization. This includes involvement with standard-setting bodies such as the ITU-T, ATIS, ETSI and the BBF. We are involved in the evolution of optical access technologies on next-generation PON. We also continue to be involved in driving optical networking, synchronization and SDN standardization and participate in industry-wide interoperability, performance-testing and system-level projects related to those standards in BBF. We are also members of MEF, TIA, CableLabs and TIP.

Manufacturing and Operations

The principal steps in our manufacturing process include the purchase and management of materials, assembly, testing, final inspection, packing and shipping. We purchase parts and components for the assembly of some products from a large number of suppliers through a worldwide sourcing program. Additionally, we manage a process that identifies the components that are best purchased directly by contract manufacturers for use in the assembly of our products to achieve manufacturing efficiency, quality and cost objectives. Certain key components used in our products are currently available from a single source, and other key components are available from only a limited number of sources. In the past, we have experienced delays in the receipt of certain key components, which has resulted in delays in related product deliveries. We attempt to manage these risks through developing alternative sources, by staging inventories at strategic locations, through engineering efforts designed to prevent the necessity of certain components and by maintaining close contact and building long-term relationships with our suppliers.

We rely on subcontractors for the assembly and testing of certain printed circuit board assemblies, sub-assemblies, chassis, enclosures and equipment shelves, and to purchase some of the raw materials used in such assemblies. We typically manufacture our lower-volume, higher-mix products and build and test product prototypes and many of our initial production units at our manufacturing site in Huntsville, Alabama. We later transfer the production of higher-volume, lower-mix assemblies to our subcontractors. Subcontract assembly operations can lengthen fulfillment cycle times, but we believe we can respond more rapidly to uncertainties in incoming order rates by selecting assembly subcontractors that have significant reserve capacity and flexibility. Our subcontractors have generally proven to be flexible and able to meet our quality requirements.

We ship the majority of products to our U.S. customers from our facilities in Huntsville, Alabama. The majority of international customers are being served from our logistics hubs in Meiningen, Germany and York, United Kingdom. We also ship directly from subcontractors to a number of customers in the U.S. and international locations. Most of our facilities are certified pursuant to the most current releases of ISO 9001, TL 9000, ISO 14001 and ISO 27001. Our Huntsville, Alabama facilities and many of our key suppliers are C-TPAT certified. Our products are also certified to certain other customers' industry and privacy standards, including those relating to the emission of electromagnetic energy and safety specifications.

Our dependence on a limited number of suppliers for certain raw materials, key components and ODM products, has prevented and may in the future prevent us from delivering our products on a timely basis, which has had and may continue to have a material adverse effect on operating results and could have a material adverse effect on customer relations. Recently, the Company has experienced increased costs on imports of certain critical raw minerals and derivative products relevant to our business and products due to tariffs imposed by the U.S. government and other nations. The availability, timing and amount of any potential refunds of such tariffs remain unclear. Moreover, although the Company has been able to substantially mitigate the impact of tariffs that have been enacted to date, if additional tariffs and reciprocal tariffs are implemented (whether as currently proposed or otherwise), such actions could have a negative effect on our financial results, including our revenue and profitability.

Competition

We compete in markets for networking and communications services and solutions for Service Providers, businesses, government agencies and other organizations worldwide. Our products and services provide solutions supporting voice, data and video communications across fiber-, copper-, and wireless-based infrastructure, as well as across wide area networks, LANs and the internet.

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We compete with a number of companies in the markets we serve. In the Subscriber Solutions category, our primary competitors include Calix, Ciena, Nokia, eero, RAD, and a growing number of Asian based ODM's selling direct to carriers. In our Access & Aggregation solutions category, key competitors include Nokia, Calix, Vecima, Harmonic and Microchip. Main competitors of our Optical Networking solutions portfolio are Ciena, Cisco, Ekinops, Nokia, Smartoptics and Ribbon Communications. Within our key target markets, we also compete less often with designated "high-risk vendors" such as Huawei and ZTE Corporation.

Across our markets and segments, the principal competitive factors can include, among others:

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differentiated feature functionality of our products and solutions;

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price performance of our solutions and lowest total cost of ownership for customers;

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quality and reliability of our products;

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financial stability and health of our company;

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ability to manage supply chains to produce and deliver products in accordance with customer wish date;

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ability to innovate and provide customers with differentiated solutions, advantageous to their business model;

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compelling technology roadmap and research and development power;

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industry thought leadership and time to market with innovative solutions;

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country of origin for products and solutions and trusted supplier status;

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security of enterprise value chain, from design to product development, support processes, to products and solutions;

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energy consumption of our products and commitment to sustainability, supporting customers in achieving their climate goals;

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customer relationship and incumbency;

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ability to deliver comprehensive solutions with a high degree of automation and ease-of-use, including hardware, software and services; and

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broad range of services and support capabilities.

Seasonality

We experience quarterly fluctuations in our revenue that occur due to many factors, including the varying budget cycles and seasonal buying patterns of our customers. More specifically, our customers tend to spend less in the first fiscal quarter as they are finalizing their annual capital spending budgets. These seasonal effects may continue to vary and do not always correlate to our operating results. Accordingly, they should not be considered a reliable indicator of our future revenue or operating results.

Foreign Currency

Transactions with customers that are denominated in foreign currencies are recorded using the appropriate exchange rates from throughout the year. Assets and liabilities denominated in foreign currencies are remeasured at the balance sheet dates using the closing rates of exchange between those foreign currencies and the functional currency with any transaction gains or losses reported in other income, net. Our primary exposures to foreign currency exchange rate movements are with the euro and the British pound sterling. Adjustments resulting from translating financial statements of international subsidiaries are recorded as a component of accumulated other comprehensive income.

Inventory

A substantial portion of our shipments in any fiscal period relate to orders received and shipped within that fiscal period for customers under agreements containing non-binding purchase commitments. Further, a significant percentage of orders require delivery within a few days.

We maintain substantial inventories of raw materials for long lead time components to support this demand and avoid expedite fees. We support our customer demand for our products by working with our suppliers, contract manufacturers, distributors, and customers to address and to limit the disruption to our operations and order fulfillment. Additionally, maintaining sufficient inventory levels to assure prompt delivery of our products increases the amount of inventory that may become obsolete and increases the risk that the obsolescence of this inventory may have an adverse effect on our business and operating results. Also, not maintaining sufficient inventory levels to ensure prompt delivery of our products may cause us to incur expediting costs to meet customer delivery requirements, which may negatively impact our operating results.

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Government Regulation

Telecommunications Matters

Our products that are incorporated into wireless communications systems must comply with various government regulations, including those of the FCC. We strive to deliver innovative network access solutions that lower the total cost and reduce the time of deploying services, increase the level of performance achievable with established infrastructures, reduce operating and capital expenses for our customers, increase network bandwidth and functionality, and extend network reach. Our development process is conducted in accordance with ISO 9001, TL 9000, ISO 14001, and ISO 27001, all of which are international standards for quality and environmental management systems.

Environmental Matters

Our products must comply with various regulations, directives and standards established by communications authorities in various countries, as well as those of certain international bodies. Environmental legislation in particular within the EU may increase our cost of doing business as we amend our products to comply with these requirements. This includes the CSRD directive, the CBAM regulation, the WEEE directive and the ESPR adopted by the EU. We are also subject to disclosure and related requirements that apply to the presence of conflict minerals in our products or supply chain. We continue to implement measures to comply with these and other similar directives and regulations from additional countries.

Global Trade

As a global company, the import and export of our products and services are subject to various laws and regulations, including international treaties, U.S. trade policy, tariffs, export controls and sanctions laws, customs regulations, and local trade rules around the world. Such laws, rules, and regulations may delay the introduction of some of our products or impact our competitiveness through restricting our ability to do business in certain places or with certain entities and individuals, or the need to comply with domestic preference programs, laws concerning transfer and disclosure of sensitive or controlled technology or source code, unique technical standards, localization mandates, and duplicative in-country testing and inspection requirements. Furthermore, material changes in such laws, rules or regulations or the failure by us to comply with such laws, rules and regulations could limit our ability to conduct business globally. Global trade policy continues to evolve and the ultimate impact of recent developments with respect to U.S. tariffs is unclear. On February 20, 2026, the United States Supreme Court issued a ruling striking down certain tariffs previously imposed under the International Emergency Economic Powers Act ("IEEPA"). The ultimate availability, timing, and amount of any potential refunds of such tariffs remain highly uncertain and are subject to further legal, regulatory, and administrative developments. Following the Supreme Court’s decision, the U.S. presidential administration announced its intention to invoke other laws to collect tariffs and announced new tariffs on imports from all countries, in addition to any existing non-IEEPA tariffs (including tariffs on semiconductors, which are expected to increase in June 2027). Furthermore, recent U.S. trade actions have triggered retaliatory actions by certain affected countries, and other foreign governments may impose further trade measures, including reciprocal tariffs, on certain U.S. goods in the future. There remains substantial uncertainty regarding the duration of existing and newly announced tariffs, potential changes or pauses to such tariffs, tariff levels, and whether further additional tariffs or other retaliatory actions may be imposed, modified, or suspended, and the impacts of such actions on our business.

AI Regulations

In the U.S., proposed federal AI regulations, such as those under consideration by Congress or agencies like the Federal Trade Commission, may impose requirements for transparency, ethical use, and data sourcing, particularly if AI systems are trained on copyrighted materials. Non-compliance could lead to restrictions on AI use, fines, or intellectual property disputes. In Europe, the EU Artificial Intelligence Act, expected to be fully implemented by 2026, categorizes AI applications by risk level and could classify our content generation as high-risk, requiring stringent compliance with safety, transparency, and accountability standards. Violations could result in fines of up to 7% of global annual revenue.

Other Regulations

As a company with global operations, we are subject to complex foreign and U.S. laws and regulations, including anti-bribery and corruption laws; antitrust or competition laws; data privacy laws and regulations, such as the GDPR and the California Consumer Privacy Act; and cybersecurity laws and regulations, among others. We have policies and procedures in place to promote compliance with these laws and regulations. To date, our compliance actions and costs relating to these laws, rules and regulations have not resulted in a material cost or effect on our capital expenditures, earnings or competitive position. Government regulations are subject to change and, accordingly, we are unable to assess the possible effect of compliance with future requirements or whether our compliance with such regulations will materially impact our business in the future.

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Sustainability

We believe that as we follow our corporate vision to enable a fully connected world, we must continue to be responsible corporate citizens. As more people are connected, work and life can be accomplished using fewer resources. We have established sustainability programs and policies that encompass the elements of Environmental, Health & Safety, Ethics, Labor, and the related management systems in alignment with the ISO 26000 Guidelines. We are committed to operating in full compliance with the laws, rules and regulations of all the countries in which we operate. The major aims of our program are reducing waste and emissions, maximizing energy efficiency and productivity and minimizing practices that can adversely affect utilization of natural resources by coming generations. Our sustainability programs are important to us, consequently, sustainability is a dedicated focus throughout the company. We have Board oversight including a Sustainability Committee, strong management support and engagement from our employees.

Areas of focus in our environmental sustainability program include:

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maintaining a dedicated Sustainability Committee of the Board of Directors;

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maintaining our mature environmental management system certified to ISO 14001:2015;

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advancing our Energy Management program with ISO 50001 readiness for the Huntsville site for 2025;

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continuing the purchase of Renewable Energy Credits, equaling ~20% of total Adtran energy consumption;

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continued use of IntegrityNext, a platform to engage suppliers to obtain an ESG assessment aligned with international standards, allowing us to monitor sustainability risks in our supply chain;

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establishing Eco-Design guidelines in the Technology organization;

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conducting Life Cycle Assessments across the portfolio;

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optimizing packaging to reduce related materials and waste;

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increasing visibility of our program internally and externally through customer engagement, joining peer sustainability groups, offering training to team members and web site enhancements; and

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participating in external CDP and EcoVadis assessments.

We expect to issue a sustainability report for 2025 in early 2026, which will use the EU ESRS guidelines, in order to fulfill the reporting obligations set forth in the EU CSRD. Within the report is information on our sustainability and governance programs, including quantitative and qualitative data for the entire Company. This information can also be found on our website at: www.adtran.com/en/about-us/esg/environmental. The information found on our website is not incorporated by reference in this report or any other report that we file or furnish to the SEC.

Human Capital

We believe that our most valuable asset is our people. To ensure we continue to succeed, our objective is to be able to recruit, hire and retain top talent. Our ability to attract and retain a high-quality workforce is dependent on our ability to maintain a diverse, equitable and inclusive workplace that provides opportunities for our employees to learn and grow in their careers. This is supported by competitive compensation and benefits, along with strong community service and other programs that enable employees to build connections within the community.

As of December 31, 2025 we had 3,338 total employees, of which 3,201 are full-time employees and 137 are part-time employees. We had 1,162 employees in the U.S. and 2,176 employees in our international subsidiaries located in North America, Latin America, EMEA and APAC regions. We also utilized 249 contractors and numerous temporary employees domestically and internationally in various manufacturing, engineering, sales and general and administrative capacities. We believe that our relationship with our employees is good. We have a diverse employee base located in 34 countries. We pride ourselves on a highly educated workforce, and the majority of our employees serve in engineering, information technology and technical roles within the organization.

As of December 31, 2025 approximately 88 employees (75%) of Adtran GmbH and Adtran Technology GmbH were subject to collective bargaining agreements of either the Association of Metal and Electrical Industry in Berlin and Brandenburg e.V. or NORDMETALL Association of Metal and Electrical Industry e.V. As of December 31, 2025, Adtran Networks had 98 employees in Switzerland, France, Italy, Finland and Spain that were subject to collective bargaining agreements of different associations. None of our other employees are subject to collective bargaining agreements.

Additionally, we continually work to recruit technical talent in diverse communities through our cooperative education program. This program seeks to identify college students that major in relevant technological areas and expose them to our work environment on an alternating semester basis. Our goal is to retain as many of these students as possible for full-time employment after graduation to build our organization's future.

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Health, Safety and Wellness

The well-being of our employees is paramount to the continued success of our business. To this end, we are committed to each of our employees' health, safety and wellness. We provide our employees with access to various health and wellness benefits designed to enable them and their family members to have affordable access to health, dental and vision insurance. Additionally, we offer access to many programs that provide additional monetary support in the event of a qualifying incident, including accident insurance, life insurance and hospital indemnity insurance, among others. We understand that mental health is an essential aspect of our employees’ well-being and we offer an employee assistance program at no charge to employees and their family members. This program provides access to qualified personnel to address various issues such as grief, financial stress, family and emotional issues.

Compensation and Benefits

We continually work to provide a competitive compensation and benefits program as this plays a key role in our ability to attract and retain a highly skilled workforce. In addition to salaries, these programs, which vary by country/region, include long-term equity incentive awards with certain vesting requirements, a 401(k) plan, healthcare and insurance benefits, health savings and flexible spending accounts, paid time off, paid volunteer time off, employee assistance program and tuition assistance. Additionally, at our global headquarters in Alabama, we offer our employees certain on-site services, including nurse practitioner care and a fitness center, among others.

Talent Development

We invest significant resources to develop the talent needed to remain a market-leading global supplier of broadband infrastructure. We offer numerous training opportunities on both technical and professional development topics. We utilize tools and processes to provide performance feedback which helps develop high potential employees into becoming our future leaders.

Our Career Development Program provides an opportunity for employees to shape their career journey. The program provides opportunities for employees to develop competencies in areas including technology, business acumen, emotional intelligence, design and systems thinking. As employees increase their competencies in these areas and master skills within their individual roles, this program offers a variety of career advancement paths.

Intellectual Property

We develop and own a significant amount of intellectual property. We have approximately 1,000 patents worldwide related to our products and over 50 additional pending patent applications. Our patents expire at various dates between 2026 and 2044. We continue to seek additional patents related to our research and development activities. We do not derive any material amount of revenue from the licensing of our patents.

The name "ADTRAN" is a registered trademark of ours and a number of our product identifiers and names. We also claim rights to a number of unregistered trademarks.

We protect our intellectual property and proprietary rights in accordance with good legal and business practices. We believe, however, that our competitive success will not fully depend on the ownership of intellectual property, but instead will depend primarily on the innovative skills, technical competence and marketing abilities of our personnel.

The communications industry is characterized by the existence of an ever-increasing volume of patent litigation and licensing activities. We have received, and may continue to receive, notices of claims alleging that we are infringing upon patents or other intellectual property. We cannot predict whether we will prevail in any claims or litigation over alleged infringements, or whether we will be able to license any valid and infringed patents, or other intellectual property, on commercially reasonable terms. It is possible that such litigation may result in significant legal costs and judgments and that intellectual property infringement claims, or related litigation against or by us could have a material adverse effect on our business and operating results.

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Information about our Executive Officers

Our executive officers as of February 26, 2026, are listed below, along with their ages on that date, positions and offices held with the Company, and principal occupations and employment, focused primarily on the past five years (and all positions within the Company).

*On July 23, 2024, Conn’s, Inc. and certain of its subsidiaries filed voluntary petitions for relief under Chapter 11 of the Bankruptcy Code.

There are no family relationships among our directors or executive officers. Adtran Networks is a majority-owned subsidiary of the Company.

Availability of Information

We file annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, proxy statements and other information as required with the SEC. The SEC maintains an internet website, http://www.sec.gov, that contains reports, proxy and information statements, and other information regarding issuers, including Adtran, that file electronically with them. Additionally, our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports, if applicable, filed or furnished pursuant to Section 13(a) or 15(d) of the Securities and Exchange Act of 1934, as amended (the "Exchange Act"), are available free of charge under the Investor Relations section of our website, www.adtran.com, as soon as reasonably practicable after we electronically file them with, or furnish them to, the SEC. The reference to our website address does not constitute incorporation by reference of the information contained on the website, which information should not be considered part of this report.