WABASH NATIONAL Corp

WABASH NATIONAL CORPORATION 3900 McCarty Lane Lafayette, Indiana 47905 Proxy Statement Summary

To assist you in reviewing the proposals that may be acted upon at our 2026 Annual Meeting, the summary below highlights certain information that is contained elsewhere in this Proxy Statement. This summary does not contain all of the information that you should consider, and you should read the entire Proxy Statement carefully before voting. Page references are supplied to help you find further information in this Proxy Statement.

Annual Meeting of Stockholders

Company Overview

Wabash National Corporation, which we refer to herein as “Wabash,” the “Company,” “us,” “we,” or “our,” is Changing How the World Reaches You®. Wabash was founded in 1985 and incorporated as a corporation in Delaware in 1991, with its principal executive offices in Lafayette, Indiana, as a dry van trailer manufacturer. Today we combine physical and digital technologies to deliver innovative, end-to-end solutions that optimize supply chains across transportation, logistics, and infrastructure markets.

To that end, we design, manufacture and service a diverse range of products supporting first-to-final mile operations, including dry freight and refrigerated trailers, platform trailers, tank trailers, dry, platform, and refrigerated truck bodies, structural composite panels and products, trailer aerodynamic solutions and specialty food grade processing equipment. In addition, through Wabash Hub, dealers and customers gain access to a nationwide parts and service network, Trailers as a Service (TaaS)SM, and advanced tools designed to streamline operations and drive growth. We have achieved this diversification through acquisitions, organic growth, and product innovation.

We believe our position as a leader in our key industries is the result of longstanding relationships with our core customers, our demonstrated ability to attract new customers, our broad and innovative product lines, our engineering leadership, and our extensive dealer and preferred partner network. More importantly, we believe our leadership position is indicative of the Values and Leadership Principles that guide our actions.

At Wabash, it’s our focus on people, purpose, and performance that drives us to do better. Our Purpose is to change how the world reaches you; our Vision is to be a premier provider of diverse solutions that optimize customers’end-to-end supply chains across transportation, logistics, and infrastructure markets and our Mission is to transform Wabash into a dynamic growth organization by merging physical products and digital technology to seamlessly serve our customers through a connected ecosystem of partners.

Our Values are the qualities that govern our critical leadership behaviors and accelerate our progress.

Our Leadership Principles are the behaviors that provide definition to our actions and bring our values to life.

Corporate Responsibility and Governance Highlights

At Wabash, it’s our focus on people, purpose and performance that drives us to do better so we can continue Changing How the World Reaches You®. We believe that our Leadership Principles, as set forth above, create a workplace culture in which our colleagues can share their talents and perspectives and are empowered to make a difference for our customers, for each other, for our communities and for our environment. Wabash is committed to growing its business in a sustainable and socially responsible manner. We support the passions and interests of our employees and empower them to be a positive influence in the world. We are proud to provide many opportunities to be good neighbors by volunteering time and talent to support the causes that matter most to our employees. We publicly disclosed substantial information about our business in our Corporate Responsibility Report, available on the Governance/Corporate Responsibility page of the Investor Relations section of our website at ir.onewabash.com, which details our commitments, programs and progress on a variety of topics, including our products and supply chain, sustainability and environmental impact, diversity and inclusion, workplace safety, ethics and compliance, risk management and governance. We have mapped our disclosures on environmental, social and governance topics to metrics outlined by the Sustainability Accounting Standards Board (SASB) and the Task Force on Climate-Related Financial Disclosures (TCFD) in our SASB and TCFD Indices, included in our Corporate Responsibility Report. The Corporate Responsibility Report is not incorporated herein by reference or otherwise. Below are some of the highlights of our focus and commitment:

• The Operations Management at each of our facilities is directly responsible for implementing this policy and ensuring full compliance with all environmental, health, and safety laws, internal standards and requirements applicable within their respective organizations. • We commit to manage all of our business activities in a responsible manner with respect for the environment through pollution prevention and with our highest priority being the health and safety of our employees. • The well-being of our employees is vital to our success. We offer a range of innovative, flexible and convenient programs aimed at supporting our employees’ holistic well-being. These programs provide tools and resources to help employees on their healthcare journey fostering engagement in beneficial, well-being-focused behaviors. • We continually focus on reducing the frequency and severity of workplace injuries and improving the workplace environment for our employees. We provide ongoing safety training and development at our production facilities, which are designed to educate and empower our employees with the knowledge and tools necessary to make safe choices and mitigate risks. Our employees are encouraged and expected to identify safety opportunities and report near-misses through our safety good catch program. • We believe that all injuries and occupational illnesses, as well as environmental incidents, are preventable. In support of this, all employees are expected to perform their work in such a manner as to not jeopardize the environment or the safety and health of themselves and their fellow workers.

• The Company utilizes a mixture of leading and lagging indicators to assess the health and safety performance of its operations. We measure OSHA Total Recordable Incident Rate (“TRIR”), which in 2025, was 4.24. We also measure our Blueprint for Excellence, which assesses a facility’s overall safety program and identifies key areas of improvement. The “Blueprint” is one of our leading indicators that helps our plants proactively measure their safety culture. Wabash utilizes a software platform (Ideagen) to strategically mitigate safety risks by understanding historical data and driving business decisions based on actionable insights and advanced analytics. • We continue to encourage reporting of near-miss incidents and track near-misses enterprise-wide. • We work to ensure that our products, processes, services, and facilities minimize the generation of waste, pollution and adverse impacts on the environment. • We invest in innovations that help protect people who operate our equipment and partner with other manufacturers in the industry to further promote safety by sharing best practices and ideas for implementing higher standards.

Our Management Approach

Our WMS is our comprehensive approach to improving how we work every day. It’s a set of principles, processes, and tools designed to help us solve problems at their root cause, reduce waste, and continuously improve our operations. WMS isn’t just about following procedures; it is about cultivating a culture where everyone, from the shop floor to the office, is empowered to identify issues, suggest solutions, and make improvements. Our WMS principles lead “The Way,” guiding our actions and decisions. These principles are supported by disciplines and processes, which, in turn, are reinforced by tools and capabilities. Combined, these principles, disciplines, processes, tools, and capabilities produce breakthrough results. Our seven key disciplines include the following: Strategic Deployment Process, Project Management, Change Management, Problem-Solving, Digital, Functional Excellence and Enterprise Processes. It is through these disciplines that we create a “One Wabash” approach for our employees and customers, add new business capabilities, and enable profitable growth. WMS puts our culture into action through a Lean mindset and respect for all, inspiring every employee to actively contribute to our enterprise transformation.

In 2022, in partnership with Purdue University, we developed a curriculum for WMS Facilitator training. Since that time, we have trained and certified over 150 facilitators as of December 2025. We have hosted numerous training sessions in 2025 and have over 800 practitioners for several of our disciplines. Company-wide, we have frequent WMS communication and engagement sessions, to keep the WMS at the forefront of everything we do.

Our One Wabash organizational structure enables long-term growth for the Company with an intense focus on streamlined processes, product innovation, and a consistent, superior experience for all customers who seek our solutions in the transportation, logistics and infrastructure markets. Our goal is to leverage standardized processes to drive consistency from customer demand through fulfillment.

Voting Matters and Vote Recommendation (page 16)

The following table summarizes the proposals to be considered at the Annual Meeting and the Board’s voting recommendation with respect to each proposal.

Board Nominees (page 17)

The following table provides summary information about each director nominee, as of the Record Date.

The table below summarizes key qualifications, skills and attributes most relevant to the decision to nominate the candidates to serve on our Board. A mark indicates a specific area of focus or experience on which the Board relies most. The lack of a mark does not mean the director nominee does not possess that qualification or skill. Each director nominee biography in this proxy statement describes each nominee’s qualifications and relevant experience in more detail.

Named Executive Officer Compensation(Say-on-Pay) (page 72)

We are asking stockholders to vote to approve, on an advisory(non-binding) basis, the compensation of our named executive officers. The primary objectives and philosophy of our compensation programs are to (i) drive executive behaviors that maximize long-term stockholder value creation, (ii) attract and retain talented executive officers with the skills necessary to successfully manage and grow our business, and (iii) align the interests of our executive officers with those of our stockholders by rewarding them for strong Company performance. In support of these objectives, in 2025, we:

Independent Registered Public Accounting Firm (page 74)

We are asking our stockholders to ratify the selection of Ernst & Young LLP as our independent registered public accountants for the year ending December 31, 2026.

Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting to Be Held on May 13, 2026.

Our Annual Report and this Proxy Statement are available at www.proxyvote.com. To access our Annual Report and Proxy Statement, enter the control number referenced on your proxy card.