Stephano Slack announced a strategic growth investment from funds managed by Madison Dearborn Partners, with additional participation from co-investor Norlantic Capital, to accelerate the accounting and advisory firm’s long-term growth strategy.
The investment will support Stephano Slack’s efforts to expand its talent base, enhance innovation initiatives and create additional opportunities for clients and employees. Financial terms of the transaction were not disclosed.
Founded in 2004 by Michael Stephano, Stephano Slack provides tax, audit, outsourced accounting and advisory services to middle-market clients. The firm was recently recognized by Accounting Today as one of the Fastest-Growing Firms of 2026 and has completed seven strategic acquisitions over the past two decades.
Stephano Slack will continue to be led by Chief Executive Officer and Managing Partner Michael Stephano. Following the transaction, the firm will adopt an alternative practice structure in which Stephano Slack, LLC will provide attest services and Stephano Slack Advisory, LLC will deliver tax, advisory and other non-attest offerings.
Industry veteran Jim Brady, former chief operating officer of Grant Thornton and a longtime Deloitte executive, will join the company as executive chairman. Brady brings 45 years of experience scaling accounting and advisory organizations and originally introduced Madison Dearborn Partners to Stephano Slack.
Madison Dearborn Partners said the investment aligns with its long-standing strategy of backing professional services businesses with broad addressable markets and operational advantages. The firm has raised more than $36 billion since its founding in 1992 and has completed more than 160 platform investments.
Advisors to the transaction included Koltin Consulting Group for Madison Dearborn Partners and Leelanau Management for Stephano Slack. Paul, Weiss, Rifkind, Wharton & Garrison, Kirkland & Ellis and Vedder Price provided legal counsel to Madison Dearborn Partners, while Pierson Ferdinand represented Stephano Slack. Freshfields advised Norlantic Capital.
KEY QUOTES:
“We were first introduced to Stephano Slack by Jim Brady, and, from our initial meeting, it was clear that Michael and his team have built a high-quality, growth-oriented business, ideally suited to MDP’s decades of experience in scaling professional services platforms with strong operational advantages and broad addressable markets. We look forward to partnering with Michael and Jim to accelerate the growth of the platform, deepen service offerings, and broaden the firm’s geographic reach into new markets.”
Vahe Dombalagian, Managing Partner and Co-Head of Financial Services, Madison Dearborn Partners
“Our partnership with MDP, a firm that understands and embodies our commitment to exceptional relationship-driven client service, adds a compelling new growth driver to the Stephano Slack platform. MDP’s support will pave new avenues for Stephano Slack to grow and diversify our platform and will foster opportunities for both our clients and employees.”
Michael Stephano, Chief Executive Officer and Managing Partner, Stephano Slack
“I’m eager to get started working alongside Michael, whom I have known personally and professionally for years, as the leader of a well-respected and growth-oriented firm. I’m confident that our combined operational experience and passion for identifying opportunities and building talented teams will add to Stephano Slack’s strengths and position the firm for continued success.”
Jim Brady, Incoming Executive Chairman, Stephano Slack
