Deloitte Expands Its $70.5 Billion ABA Platform Strategy

The Firm

NEW YORK — Deloitte Touche Tohmatsu Limited reported $70.5 billion in aggregate global revenue for the fiscal year ending May 31, 2025, a 4.8 percent increase in local currency from FY2024. The firm’s U.S. subsidiary, Deloitte LLP, recorded $35.7 billion in U.S. revenues, more than most Fortune 500 companies generate globally. Deloitte operates in more than 700 locations across 150 countries and territories, employing over 470,000 professionals.

It is the largest of the Big Four accounting firms, ahead of PwC ($56.9 billion in FY2025), EY ($53.2 billion in FY2025), and KPMG ($39.8 billion in FY2025).

Founded in London in 1845 by William Welch Deloitte, the firm grew through a series of mergers, combining with Haskins & Sells in 1972 and Touche Ross in 1989 into the most broadly resourced professional services network in the world. Deloitte today serves nearly 90 percent of the Fortune Global 500 and thousands of private companies. Its U.S. practice alone employs more than 156,000 professionals across more than 100 offices, giving it broad geographic coverage for multi-state transaction support.

In FY2025, Deloitte reorganized its services around four global business units: Audit & Assurance; Tax & Legal; Strategy, Risk & Transactions (SR&T); and Technology & Transformation. Transaction advisory work, including quality of earnings, financial due diligence, and M&A advisory across the deal lifecycle, sits within SR&T. Deloitte Corporate Finance LLC, a separately registered broker-dealer subsidiary, provides strategic M&A advisory and investment banking services. The multi-entity structure allows the firm to address every phase of the deal lifecycle, from target identification through post-close integration, under one organizational umbrella.

The Behavioral Health Practice

What separates Deloitte from other Big Four firms in ABA due diligence is its explicitly branded behavioral health solutions practice. The firm staffs the practice with former behavioral health agency leaders, clinicians, and technologists who specialize in the operational, clinical, and regulatory dimensions of behavioral health delivery. The practice focuses on helping federal, state, and local agencies build integrated systems for mental health and substance use disorder services.

That specialization matters in ABA. Behavioral health platforms being evaluated for acquisition typically face complex regulatory overlays: Medicaid billing compliance, state licensure requirements, BCBA supervision ratios, documentation standards, and payer credentialing. Deloitte’s behavioral health team brings operational knowledge of those regulatory layers that most generalist transaction advisory teams lack. For PE buyers evaluating large ABA platforms with Medicaid-heavy revenue mixes, the combination of financial diligence rigor and behavioral health operational expertise is difficult to replicate at other firms.

Deloitte also advises state Medicaid agencies on rate-setting, benefit design, program integrity, and managed care implementation through its State Health Care Transformation Services practice. The firm provides actuarial models for waivers and State Plan Amendments, managed care readiness reviews, provider readiness tools, and provider financial performance dashboards. That government advisory work gives Deloitte direct insight into the regulatory decisions that shape ABA reimbursement, accreditation mandates, and compliance requirements, intelligence that informs its transaction advisory work when evaluating ABA targets and their exposure to regulatory change.

Deloitte’s behavioral health practice is staffed with former agency leaders and clinicians who understand the operational and regulatory dimensions of behavioral health delivery, a specialization that most generalist transaction advisory teams lack and that has become increasingly central to ABA platform due diligence.

Transaction Advisory Capabilities

Deloitte’s transaction advisory team provides the full spectrum of deal support across the M&A lifecycle. On the buy side, Deloitte delivers quality of earnings analysis, adjusted EBITDA assessment, net working capital and debt-like item analysis, purchase agreement review, and post-acquisition accounting support including post-close working capital true-ups and opening balance sheet preparation. On the sell side, the firm prepares vendor due diligence reports, financial fact books, and seller-ready financial packages designed to accelerate deal timelines and maximize seller proceeds.

Deloitte’s SR&T practice grew 5.5 percent in local currency in FY2025, reflecting demand for M&A advisory and risk services. Mergermarket has historically ranked Deloitte at the top of the global financial advisor league table by deal volume, including #1 finishes in 2018, 2020, and 2022. In the FY2025 Mergermarket rankings released January 2026, that top spot moved to PwC with 660 deals, followed by KPMG (525) and Goldman Sachs (515); Deloitte recorded 478 deals, finishing fourth. The firm has also been recognized as a leading advisor in Life Sciences & Healthcare in multiple years.

AI-driven analytics now sit at the center of the firm’s due diligence methodology, used to process large volumes of financial and operational data during diligence reviews. For healthcare transactions, this includes analysis of payer mix concentration, revenue cycle metrics, claims denial patterns, CPT code utilization trends, and patient census data. In ABA transactions, where reimbursement is heavily concentrated in Medicaid fee-for-service and managed care contracts, that analytical capability allows Deloitte’s teams to evaluate revenue sustainability and identify billing pattern anomalies with a granularity smaller advisory firms cannot match.

Integration and separation services follow the diligence work. For PE-backed ABA platforms executing bolt-on acquisitions, integration planning is often as critical as the initial diligence. Deloitte’s integration teams help buyers consolidate clinical operations, billing systems, electronic health record platforms, HR systems, and compliance programs across multiple acquired entities. In ABA roll-ups that may involve dozens of practices across multiple states with different Medicaid programs, licensure requirements, and supervision ratio mandates, that integration capability is a meaningful differentiator.

The firm has committed more than $3 billion in investments in generative AI through fiscal year 2030, including the development of the Zora AI platform, an agentic AI product business built on the NVIDIA AI stack. For complex ABA platform transactions with multiple entities, thousands of Medicaid claims, and multi-state regulatory compliance requirements, AI-augmented diligence offers a meaningful edge in both speed and depth of analysis.

Where Deloitte Fits in ABA M&A

Deloitte’s ABA work is concentrated at the top of the market, on large platform transactions involving institutional PE sponsors such as Blackstone, KKR, Bain Capital, and Charlesbank Capital Partners, or strategic acquirers evaluating transformative healthcare deals. These are transactions where target enterprise value typically exceeds $500 million and where the complexity (multi-state operations, Medicaid compliance layers, clinical workforce dynamics, and regulatory risk) requires the breadth of a Big Four platform.

For mid-market ABA transactions in the $10 million to $150 million EBITDA range that constitute the majority of deal activity in the sector, Deloitte is less frequently engaged as the primary QofE provider. The firm’s fee structure and resource allocation model are calibrated for larger engagements. In that segment, PE buyers more commonly engage national firms like RSM, BDO, or Grant Thornton for financial due diligence, sometimes layering in Deloitte or another Big Four firm for specific workstreams such as tax structuring, regulatory diligence, or post-close integration advisory.

Deloitte’s engagement footprint in ABA extends beyond the financial QofE. Its forensic practice, housed within Deloitte Financial Advisory Services LLP, handles billing pattern analysis, documentation compliance, and claims integrity for transactions where program integrity concerns exist. The HHS Office of Inspector General is running a seven-state ABA audit series; four audits had been completed by February 2026 (Indiana, Wisconsin, Maine, and Colorado), and every completed audit found improper or potentially improper claim lines in 100 percent of sampled enrollee-months. Forensic accounting and compliance diligence have become standard components of ABA deal evaluation for sophisticated buyers as a result.

Competitive Positioning

Among the Big Four, Deloitte competes with PwC, EY, and KPMG for large-cap healthcare transaction advisory mandates. PwC’s Deals practice handles thousands of transactions annually and publishes a healthcare M&A outlook widely cited in the sector. Daniel Farrell, PwC’s U.S. Health Services Deals Leader, has flagged behavioral health, physician services, and tech-enabled care delivery as the subsectors drawing the most aggressive capital flows in 2026. EY-Parthenon, the firm’s strategy and transactions arm, runs integrated commercial and financial due diligence and has worked extensively with PE clients in healthcare. KPMG’s Healthcare Deal Advisory & Strategy practice is led by Ross Nelson, MD, MBA, who brings clinical training to deal evaluation.

Deloitte’s differentiator against those competitors is its explicit behavioral health practice branding, the depth of its state Medicaid advisory work, and the firm’s AI investment trajectory. While all Big Four firms run healthcare transaction teams, Deloitte is the firm most likely to have team members who have worked directly on the state-level regulatory infrastructure (rate-setting, benefit design, program integrity reviews) that governs ABA reimbursement. That is not theoretical advisory capacity. It is operational experience with the agencies that set the rules.

The strategic value Deloitte brings to ABA transactions extends beyond the diligence report. Its relationships with state Medicaid agencies and its actuarial and reimbursement advisory capabilities allow it to contextualize diligence findings within the broader regulatory environment, intelligence that can be deal-defining.

Deloitte’s Life Sciences & Health Care practice also produces research and thought leadership that shapes how the market reads ABA-related dynamics. The Deloitte Center for Health Solutions publishes analyses of healthcare spending trends, consumer behavior, and regulatory shifts that provide context for healthcare M&A activity. For PE sponsors building ABA investment theses, that research offers data-driven perspectives on autism prevalence trends, Medicaid spending trajectories, and the policy environment facing behavioral health providers, intelligence that complements the firm’s deal-level advisory work.

Key Considerations for ABA Stakeholders

For ABA practice owners contemplating a sale, Deloitte is unlikely to be the firm preparing the QofE report unless the transaction involves a large institutional buyer or a platform with enterprise value north of several hundred million dollars. The firm’s fee structure and engagement model are calibrated for large, complex transactions. Owners selling to mid-market PE firms will more commonly encounter national or regional advisory firms handling their financial due diligence.

For PE sponsors evaluating ABA platform acquisitions, Deloitte’s behavioral health practice and Medicaid advisory expertise make it a strong choice for regulatory and operational diligence workstreams, even when another firm handles the primary financial QofE. That layered approach (a mid-market specialist for financial diligence and a Big Four firm for regulatory, tax, and integration advisory) is increasingly common as the regulatory environment facing ABA providers grows more complex with accreditation mandates, rate cuts, and federal audit scrutiny.

For investors evaluating ABA platforms in states with active Medicaid reform, including Indiana’s accreditation mandate and rate cuts, Massachusetts’s accreditation requirements, and the OIG’s ongoing seven-state audit series, Deloitte’s government advisory relationships and behavioral health operational expertise provide a diligence layer few other advisory firms can deliver. The firm’s scale, its forensic capabilities, and its AI-augmented analytics position it as the most comprehensively resourced option for ABA transactions at the institutional end of the market.

Three audits in the OIG’s seven-state ABA series remain in progress. With PwC forecasting an inflection point for health services dealmaking in 2026, Deloitte’s behavioral health and forensic teams are positioned for the institutional-tier ABA transactions that will follow.

AT A GLANCE

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