What Stephano Slack LLC does

Stephano Slack LLC is a regional accounting and advisory firm founded in 2004 and headquartered in Wayne, Pennsylvania, operating across the Mid-Atlantic tri-state region (Pennsylvania, New Jersey, Delaware) with offices in Wayne, Marlton, Wilmington, and Oreland. The firm delivers professional services in four core streams: audit and attest services, tax compliance and advisory, outsourced accounting (under the StephanoPlus sub-brand), and business advisory including CFO advisory, business valuations, and transaction support. Service delivery is partner-led, with a sales-led go-to-market model that relies on direct client engagement, professional referrals (attorneys, banks, investment counselors), and serial acquisitions that expand the partner bench and geographic footprint. Five acquisitions between December 2023 and December 2025 — Morgenstern Waxman Ellershaw, Gold Gerstein Group, Boyer & Boyer, Kimmel Lorah & Associates, and CL Rotz and Associates — have established a Tri-State footprint and meaningfully scaled the practice.

The firm is differentiated by deep vertical specialization in construction, real estate, manufacturing and distribution, life sciences/biotech, nonprofits, and professional services firms, with industry-specific compliance expertise such as job-cost accounting, government grant accounting, and R&D tax credits. The client base is predominantly mid-market and enterprise across these verticals, supplemented by high-net-worth individuals seeking estate planning and complex tax strategy. Pricing is quote-based, customized per engagement, and not publicly disclosed, with multi-year contracts for audit and outsourced accounting engagements. The technology stack relies on standard accounting software, cloud-based client portals (e.g., ClientAxcess), document management systems, and CPACharge for payments — none of which constitute proprietary technology assets. StephanoPlus represents the firm's primary productized offering, providing flexible weekly-to-monthly outsourced accounting that functions as an extension of client teams.

In June 2026, Stephano Slack received a strategic growth investment from Madison Dearborn Partners with participation from Norlantic Capital, adopted an alternative practice structure (separating Stephano Slack LLC for attest services from Stephano Slack Advisory LLC for tax and business consulting), and brought in Jim Brady (former Grant Thornton COO, longtime Deloitte executive) as Executive Chairman. The firm concurrently launched a Human Resources Advisory Services practice led by Alain Duroseau and was ranked #13 on Accounting Today's Fastest-Growing Firms 2026 list. Recognition also includes Top Workplaces 2022 and 2025, Silver Philly Favorites Award, and INSIDE Public Accounting Top 400 placement in 2024, reflecting a brand-aware growth strategy anchored in talent, vertical expertise, and regional roll-up consolidation rather than proprietary technology.

Name

Stephano Slack LLC

Legal name

Stephano Slack LLC

Website

https://stephanoslack.com

Company type

Private

Founded year

2004

Operating status

Operating

Headcount range

101–250 employees

Short description

Stephano Slack LLC is a Wayne, Pennsylvania-based accounting and advisory firm serving mid-market and enterprise clients across construction, real estate, manufacturing, life sciences, nonprofits, and professional services in the PA/NJ/DE tri-state region, offering audit, tax, outsourced accounting (StephanoPlus), and business advisory services.

Ownership category

akta.pro rank

Headquarters

HQ city

Wayne

HQ country

United States

HQ region

North America

Offices4 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Marketing or Sales, Technology or R&D, Infrastructure

Revenue model

1. Audit and Attest Services: Audit, review, compilation, and agreed-upon procedure services delivered through Stephano Slack LLC, a licensed independent CPA firm providing attest services to clients.
2. Tax Compliance and Advisory: Tax planning, preparation, and advisory services including federal, state, and local tax compliance for individuals, businesses, and organizations.
3. Outsourced Accounting (StephanoPlus): Back-office accounting services ranging from partial support to full outsourcing on interim or permanent basis, with flexible engagement models and weekly to monthly service options.
4. Business Advisory Services: Advisory services including business valuations, CFO advisory, human resources consulting, and transaction advisory.

Pricing tiers

Go-to-market motion2 records

Distribution channels3 records

Marketing channels6 records

Core offering

Stephano Slack LLC is a regional accounting and advisory firm providing audit and attest services, tax compliance and planning, outsourced accounting through its StephanoPlus sub-brand, business valuations, CFO advisory, transaction advisory, and human resources advisory services. The firm serves mid-market and enterprise clients across construction, real estate, manufacturing, life sciences, professional services, and nonprofit sectors in Pennsylvania, New Jersey, and Delaware.

Product overview

Stephano Slack LLC operates as a regional accounting and advisory firm offering a comprehensive suite of professional services. The core offering consists of traditional accounting, audit, and tax services supplemented by specialized practice areas. The firm operates two primary branded service lines: (1) Stephano Slack for core accounting, audit, tax compliance and planning, and advisory services, and (2) Stephano Plus for outsourced accounting solutions. Additional specialized modules include Human Resources Advisory Services (launched June 2026) and Valuation Services. The firm serves industries including construction, real estate, manufacturing, distribution, life sciences, professional services, and nonprofits across Pennsylvania, New Jersey, and Delaware.

Differentiator

Problem solved

Functional benefit

Brands

• StephanoPlus: Outsourced accounting services division providing back office support and full outsourced accounting function on an interim or permanent basis.

Products and services

• Stephano Slack Core Accounting, Audit, Tax and Advisory Services Full-service accounting and advisory firm providing audit and attest services, tax compliance and planning, and specialty advisory services for industries including construction, real estate, manufacturing, life sciences, professional services, and nonprofits. Delivered through Stephano Slack LLC (attest services) and Stephano Slack Advisory LLC (tax and business consulting).
• StephanoPlus Outsourced Accounting Outsourced accounting services functioning as an extension of client teams, offering back-office support and full outsourced accounting function on an interim or permanent basis. Flexible engagement models range from weekly to monthly service, delivered through a cloud-based client platform.
• Human Resources Advisory Services Practice Human resources strategy, talent acquisition, employee engagement, organizational effectiveness, change management, and training and professional development programs for clients across public, private, nonprofit, and higher education sectors.
• Valuation Services Business valuation services for purchase or sale of businesses, gift and estate tax purposes, buy/sell agreements, charitable contributions, succession planning, and financial reporting. Delivered by Certified Valuation Analyst (CVA) credentialed professionals and partners with ABV and CFF credentials.

Quantifiable outcome

• Ranked #13 among 25 firms on Accounting Today's Fastest-Growing Firms 2026 list
• +2 more outcomes

Named customers5 records

Segments7 records

Ideal customer profiles6 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature2 records

Partnerships

Two partnerships are on record, tiered flagship and core.

• Jim BradyflagshipOthersIndustry veteran Jim Brady, former COO of Grant Thornton and longtime Deloitte executive, joined as executive chairman. With 45 years of experience scaling professional services organizations, he will leverage his expertise to support firm growth.
• CPAmerica, Inc.coreOthersStephano Slack is a member firm of CPAmerica, an association of independent CPA firms with 90 member firms across the United States. The association provides resources, peer networking, and recognition opportunities for member firms.

Scale indicators4 records

Recent moves7 records

Expansion highlights6 records

Direct peers

• Baker Newman Noyes: Northeast regional CPA firm with similar full-service audit, tax, and advisory offering plus outsourced accounting. Comparable size and PE-style growth ambition through M&A, with overlapping target verticals like nonprofits and professional services.
• WithumSmith+Brown: Mid-Atlantic regional CPA firm (headquartered in New Jersey) with comparable headcount, full-service audit/tax/advisory offering, and similar mid-market to enterprise client mix across the same Tri-State geography. Strong vertical specialization overlap.
• Kreischer Miller: Pennsylvania-based regional CPA and advisory firm serving closely overlapping Mid-Atlantic industries (construction, manufacturing, nonprofits, family-owned businesses). Comparable size, full-service mix (audit, tax, outsourced accounting, advisory), and similar partner-led GTM make it the closest direct peer.
• Sax LLP: New Jersey-based CPA and advisory firm of comparable size serving construction, real estate, manufacturing, and nonprofit clients. Direct overlap in Tri-State geography, service mix, and target customer segments including HNW individuals and mid-market enterprises.

Emerging players

• Marks Paneth: New York-based mid-market CPA firm that received a growth investment from New Mountain Partners. Highly comparable PE-backed regional CPA with audit, tax, advisory, and outsourced accounting services targeting similar middle-market and HNW clients.
• Citrin Cooperman: PE-backed (New Mountain Partners) mid-market CPA firm pursuing an aggressive acquisition strategy in advisory services. Closely comparable to Stephano Slack's growth playbook, alternative practice structure, and use of private capital to fund roll-up M&A, though larger and national.
• Wipfli LLP: Top 20 US accounting firm with PE backing from Thoma Bravo and a similar acquisitive growth strategy focused on mid-market audit, tax, outsourced accounting, and advisory. Comparable service mix and customer profile, but materially larger and more national.

Broad incumbents

• Grant Thornton: Top 6 US accounting firm offering audit, tax, and advisory services to mid-market clients. Stephano Slack's executive chairman Jim Brady is a former Grant Thornton COO, indicating deep cultural and competitive overlap in target verticals and service lines.
• BDO USA: Top-tier US accounting firm with overlapping audit, tax, and advisory services for mid-market and enterprise clients across the same industries. Stephano Slack actively recruits from BDO (e.g., former Director of Assurance partner) and competes with it for the same client base, though BDO is far larger.
• RSM US: Top 5 US accounting firm focused on the middle market with comparable audit, tax, and advisory offerings plus outsourced accounting. Direct competitor for the same mid-market enterprise clients in construction, real estate, manufacturing, and nonprofit verticals.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/427960
• Instagraminstagram.com/stephanoslack
• Xx.com/stephanoslack

Revenue estimate

Valuation estimate

Number of profiles

Profiles13 records

Subsidiaries2 records

Funding overview

Funding rounds1 record

Investors1 record

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Stephano Slack LLC