Orange County, CA
Located in the heart of Irvine’s business district, Withum is one of the nation’s top-rated and largest accounting firms in Orange County.
Withum helps local corporations and nonprofits thrive, offering advisory, tax, audit, assurance and consulting services to the Orange County business community. We are more than just an Irvine accounting firm, we are a strong national resource providing all the traditional CPA and accounting services businesses and individuals require, plus a whole suite of advisory solutions to accelerate your success. That’s the Power in the Plus!
Orange County Service Specializations
CA State and Local Tax Updates
Do you or your organization operate in multiple states? Do you own property in a variety of states? California 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 California 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 Orange County
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
Kenneth L. Johnson, CPAKen is the Partner-in-Charge (PIC) of the firm’s Orange County office. Ken brings nearly three decades of expertise in conducting audits and reviews for both privately held and publicly traded companies.
In addition to his successful career working with and advising the firm’s clients, Ken dedicates much of his time to non-client-focused activities, such as the daily operations and people strategy of the Orange County office and its growth in the local marketplace. He is passionate about mentoring the next generation and providing them with the same opportunities he had. Ken is helping the younger team members grow the firm and contribute to this office’s legacy of entrepreneurship. By acting as a business owner first, he is setting an example to the office of the advisory experience we should bring to our clients, above and beyond the compliance work of audits and tax.
Orange County Leadership
Withum in the News
ROI-NJ Names Withum Leaders to Annual Power List
Pat Walsh Pat Walsh, Managing Partner and CEO, has led numerous firmwide strategic initiatives focused on best practices, client experience and technology. He leads Withum’s national growth strategy and client service initiatives, with a focus on innovation, talent development and expanding the Firm’s advisory capabilities to meet clients’ evolving needs. Pat was recognized for his…
Withum Recognized with Cigna Healthy Workforce Designation™
As a people-first organization, the Firm offers a competitive Total Rewards benefits package with unique perks for Withum team members, recognizing wellness extends beyond baseline healthcare benefits. Withum is proud to be at the forefront of exceptional benefits that support team members’ health journeys. In addition to its traditional medical, dental and vision plans, the Firm offers supplemental benefits. These include an…
Rochester Business Journal Names Withum Leaders on Accounting and Insurance 2026 Power List
Rich Wright Rich Wright is the Partner-in-Charge of Withum’s Buffalo, Rochester and Batavia offices, offering more than 30 years of public accounting experience and deep expertise in tax planning. He advises closely held businesses, high-net-worth individuals and business owners on complex tax compliance and advisory matters across multiple industries. A strategic, people-focused leader, Rich plays…
Forbes Names Thirteen Withum Leaders to Its Best-In-State CPAs List
Withum’s representation reflects the Firm’s collective power of people, reinforcing its position as a leading national advisory, tax and audit firm. From the East to the West Coast and representing a broad cross-section of services and industries, the Withum advisors listed reflect diverse expertise and leadership styles, united by a shared commitment to client and community service. Withum’s 2026 Best-In-State CPAs New Jersey New…
LA Times Names Two Withum Leaders on its Banking and Finance Visionaries List
About Aza Ghazaryan Aza Ghazaryan is a Tax Partner with over 20 years of experience serving as a trusted advisor to partnerships and high-net-worth individuals on tax planning and compliance. She advises clients across industries, including professional services, real estate, technology and not-for-profit. Aza has successfully guided clients and teams through complex regulatory changes, including the Tax Cuts and Jobs Act, federal…
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