Tax Services
East Brunswick, NJ
Located off the NJ Turnpike on Route 18 in East Brunswick, Withum is one of New Jersey’s largest accounting and advisory firms — and among the top firms in the nation.
Together, we’ll bolster your business plans, navigate ever-changing rules and regulations and anticipate the future of your industry. Our professionals embrace a bold, forward-thinking mindset rooted in integrity and a commitment to excellence. We go beyond traditional services to drive growth and innovation — plus, we offer a whole suite of advisory solutions to level up your success. That’s the Power in the Plus!
East Brunswick Service Specializations
Assurance and Accounting
Business Enterprise Advisors
Outsourced Accounting Systems and Services (OASyS)
New Jersey State and Local Tax Updates
Do you or your organization operate in multiple states? Do you own property in a variety of states? New Jersey State and Local Tax (SALT) laws are always changing and understanding the nuances of the states that you own or operate in is challenging. In these New Jersey resources, you’ll find just a dash of the most up-to-date details on rules and regulations as state and local tax changes happen by state!
Industries We Focus on in East Brunswick
Beyond the Region
- Inside Public Accounting Top 100 Firms – 22nd Largest Nationally
- Accounting Today Top 100 Firms – 22nd Largest Nationally
- Great Place to Work® – Fortune Best Workplaces for Parents and Women
- Vault Top 25 Accounting Firm
Partner In Charge
John M. Mortenson, CPAJohn is the partner-in-charge of our East Brunswick, NJ, office. In addition, John is the Practice leader for the Assurance and Accounting Services for the firm. In this capacity, his responsibilities include overseeing the delivery of all accounting and auditing services to the firm’s clients and include ensuring the firms system of quality control adhere to all professional standards. He has more than 30 years of professional experience. John provides accounting, auditing, tax and business advisory services to many industries, including pharma, biotech, insurance, manufacturing and distribution companies, and also has experience working with SEC reporting companies.
In his community, John is President of the Board of Directors of Embrace Kids Foundation, a not-for-profit organization supporting children with cancer and blood disorders. He resides in Monmouth County, NJ.
East Brunswick Leadership
Withum in the News
Stephanie Mansour Named a Financial Services Woman to Watch by Providence Business News
Stephanie is a growth driver at Withum, leading audit engagements across various industries, including not-for-profit, industrial and consumer products, healthcare and employee benefit plans. She brings a strategic approach to identifying risk and performing internal control testing to support accurate, reliable financial reporting for her clients. Stephanie oversees complex engagements while working with her team…
Withum Announces 2026 Firmwide Leadership Transitions
This next generation of leaders step forward at a pivotal time for the Firm, bringing the technical expertise and strategic perspective needed to navigate continued growth, rapidly advancing technology and an ever-evolving industry landscape. Grounded in the Withum Way mentality, they will shape what’s ahead while preserving the culture that remains central to how the…
Withum Names Eighteen New Partners
Introducing Our 18 New Partners
Withum’s Columbia Office Welcomes Greater Baltimore
Withum team members, clients and community leaders, including representatives from Howard County and the Central Maryland Chamber, came together to mark the official “door opening” on the new location. The ribbon-cutting ceremony highlighted the evening, which featured citations presented by community leaders welcoming Withum to the Columbia region and recognizing its strong ties to the…
Nadia Matthie Appointed as Chair of the AICPA’s Employee Benefit Plans Expert Panel
The AICPA’s Employee Benefit Plans Expert Panel was formed to protect the public interest and agree on key plan issues by leveraging the knowledge of leaders in the employee benefit plan industry. Nadia’s deep expertise makes her a valuable asset to help further the panel’s mission as Chair of the group. Nadia has more than…
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