The top ten accounting firms in the USA in 2026 are Deloitte, PwC, EY, KPMG, RSM US, BDO USA, Grant Thornton, CBIZ/MHM, Forvis Mazars, and CliftonLarsonAllen (CLA). The Big 4 —Deloitte, PwC, EY, and KPMG—dominate the global market, collectively generating over $175 billion in annual revenue.
What Are the Top Accounting Firms in the USA?
The United States is home to some of the world’s most powerful accounting and professional services firms. From the trillion-dollar audit practices of the Big 4 to the agile mid-market CPA firms serving American small and mid-sized businesses, the landscape is vast, competitive, and constantly evolving.
Whether you are a CFO evaluating audit partners, a business owner shopping for tax advisory services, a student choosing a career path, or a growing company weighing ERP and financial automation tools, understanding which major accounting firms in the US there are, what they do, and how they compare is essential.
This guide covers every major query you might have: the Big 4, the Big 6, the top 5, the largest accounting companies in America, regional leaders in NYC, Los Angeles, Chicago, and beyond — all in one place, updated for 2026.
The Top Ten Accounting Firms in the USA (2026 Rankings)
Below is the definitive ranking of the largest accounting firms in the US, ordered by annual US revenue and global market influence.
| Rank | Firm | US Revenue (Est. 2025) | Global Revenue | Employees (Global) | HQ |
|---|---|---|---|---|---|
| 1 | Deloitte | ~$33 billion | $70.5 billion | 460,000+ | New York, NY |
| 2 | PwC | ~$24 billion | $55+ billion | 370,000+ | New York, NY |
| 3 | EY | ~$24 billion | $49+ billion | 400,000+ | New York, NY |
| 4 | KPMG | ~$15 billion | $39.8 billion | 275,000+ | New York, NY |
| 5 | RSM US | ~$4 billion | $7.7 billion | 16,000+ | Chicago, IL |
| 6 | BDO USA | ~$3 billion | $14+ billion | 115,000+ | Chicago, IL |
| 7 | Grant Thornton | ~$2.5 billion | $8.5 billion | 73,000+ | Chicago, IL |
| 8 | CBIZ / MHM | ~$2 billion | N/A | 6,000+ | Cleveland, OH |
| 9 | Forvis Mazars | ~$2 billion | $6+ billion | 7,500+ | Springfield, MO |
| 10 | CliftonLarsonAllen (CLA) | ~$1.5 billion | N/A | 8,500+ | Minneapolis, MN |
Revenue figures are based on the most recent fiscal year reporting and IPA 500 data.
1. Deloitte — The Largest Accounting Firm in the USA
Deloitte is the undisputed number one accounting firm in the United States and the world. With US revenues estimated at approximately $33 billion in 2025 and global revenues reaching $70.5 billion for fiscal year 2025, Deloitte operates at a scale no competitor can match.
Founded: 1845 (as William Welch Deloitte’s practice in London) US Headquarters: New York City, NY Global Employees: 460,000+ Key Services: Audit & Assurance, Tax Advisory, Risk & Financial Advisory, Management Consulting, Technology Consulting
Deloitte’s competitive edge lies in its technology investment. The firm has pioneered the use of artificial intelligence, cloud computing, and advanced data analytics within professional services — capabilities that rival those of the world’s top management consulting firms like McKinsey and BCG. Their consulting arm is so substantial that it competes directly in sectors far beyond traditional accounting.
Best for: Fortune 500 enterprises, publicly traded companies, multinational corporations, and organizations requiring integrated audit, tax, and technology advisory.
2. PwC (PricewaterhouseCoopers) — The Audit Leader
PricewaterhouseCoopers, commonly known as PwC, holds the second position among major accounting firms in the US and has been consistently named one of the best public accounting firms in the world. Their US revenues are estimated at $24+ billion, with global revenues surpassing $55 billion.
Founded: 1998 (merger of Price Waterhouse and Coopers & Lybrand) US Headquarters: New York City, NY Global Employees: 370,000+ Key Services: Audit & Assurance, Tax Services, Deals (M&A Advisory), Consulting, Digital Transformation
PwC commands the largest audit practice among the Big 4, serving the majority of Fortune Global 500 companies. Vault has acclaimed PwC as the best firm in public accounting for 2026, and the firm is also recognized for its ESG reporting capabilities and digital transformation advisory.
Best for: Large corporations needing external audit services, organizations undergoing mergers and acquisitions, and businesses requiring regulatory compliance expertise.
3. EY (Ernst & Young) — Strategy and Transactions Powerhouse
Ernst & Young, known globally as EY, is the third-largest accounting firm in the US and one of the most respected names in professional services worldwide. EY’s US revenues are estimated at $24 billion, with global revenues at approximately $49 billion.
Founded: 1989 (merger of Ernst & Whinney and Arthur Young & Co.) US Headquarters: New York City, NY Global Employees: 400,000+ Key Services: Assurance, Tax, Strategy & Transactions, Consulting, Technology Risk
EY has been recognized for 25 consecutive years by Fortune magazine as one of the best companies to work for. A landmark milestone in 2024 saw Janet Truncale become the firm’s first female global chair and CEO, underscoring EY’s commitment to inclusive leadership. The firm’s Climate Change and Sustainability Services practice is among the most advanced in the industry, helping clients navigate ESG and green reporting frameworks.
Best for: Mid-sized to large companies seeking M&A advisory, strategy consulting, or sustainability reporting. Also popular among professionals seeking strong career development.
4. KPMG — The Risk, Tax, and Financial Services Specialist
KPMG — an acronym for Klynveld, Peat, Marwick, and Goerdeler — rounds out the Big 4 accounting firms. The firm generated approximately $15 billion in US revenues and $39.8 billion globally in 2025.
Founded: 1987 US Headquarters: Midtown Manhattan, New York City, NY Global Employees: 275,000+ Key Services: Audit, Tax, Advisory, Risk Management, Deal Advisory, ESG
KPMG is particularly well-regarded for its tax advisory and risk consulting capabilities, especially among financial services firms, healthcare organizations, and government entities. The firm has invested heavily in tech infrastructure and ESG initiatives over the past two years, driving strong incremental growth.
Best for: Financial institutions, healthcare organizations, and businesses that need expert guidance on cross-border tax compliance or regulatory risk.
Understanding the Big 4 Accounting Firms
The term “Big 4” refers to Deloitte, PwC, EY, and KPMG — the four largest professional services and accounting networks in the world. Together, these four firms:
- Audit the vast majority of publicly listed companies in the US and globally
- Generate a combined global revenue exceeding $175 billion annually
- Employ over 1.5 million professionals across 150+ countries
- Hold an estimated 67% share of the global accountancy market
Historically, the profession was known as the Big 8, which consolidated through mergers to the Big 6 (when Price Waterhouse merged with Coopers & Lybrand, and Deloitte merged with Touche Ross), and then to the Big 5 before the collapse of Arthur Andersen following the Enron scandal in 2002 left the current Big 4.
The Top 5 Accounting Firms in the USA
When Americans ask about the top 5 accounting firms in the US, the answer is almost always the same in 2026:
- Deloitte — largest by revenue, consulting-heavy
- PwC — strongest audit practice, Fortune 500-focused
- EY — strategy, transactions, and sustainability
- KPMG — risk, financial services, and tax specialist
- RSM US or BDO USA — competing for the fifth spot in the national ranking
The Big 4 plus RSM or BDO represent the core of what decision-makers mean when discussing the top five major auditing firms in America.
5. RSM US — The Premier Middle-Market Accounting Firm
RSM US is the fifth-largest accounting firm in the United States and the leading CPA firm focused exclusively on the middle market. The firm reported North American revenues of approximately $4 billion in 2025, and its global network (RSM International) generated $7.7 billion globally.
Founded: 1926 US Headquarters: Chicago, IL Key Services: Audit, Tax, Consulting, Risk Advisory, Technology, and Management Consulting Employees: 16,000+ (US)
RSM’s differentiation lies in its singular focus on middle-market businesses — companies with revenues typically between $10 million and $1 billion. This makes RSM the most relevant choice for growing US businesses that have outgrown local CPA firms but don’t need the complexity (or cost) of the Big 4.
Best for: Mid-sized private companies, private equity-backed businesses, and family-owned enterprises seeking enterprise-grade accounting with a personal-service feel.
6. BDO USA — The Global Mid-Market Alternative
BDO USA is the sixth-largest accounting firm in the US, with reported fiscal year 2025 revenues of $3.018 billion. The firm expects continued growth through strategic combinations and increased client demand across advisory services.
Founded: 1910 (US practice) US Headquarters: Chicago, IL Global Network: 1,400+ offices in 150+ countries Key Services: Assurance, Tax, Advisory, Digital Solutions, Outsourcing
BDO is particularly strong in mergers and acquisitions, business restructuring, and complexity management. Their flexible service structure makes them an excellent fit for SMEs, private companies, and growing enterprises that need scalable support without Big 4 overhead.
Best for: Mid-market businesses, private equity portfolio companies, and organizations looking for flexibility across international markets.
7. Grant Thornton — The Independent Assurance and Advisory Firm
Grant Thornton LLP is one of the oldest accounting firms in the United States, founded in 1924. The firm’s global network reported record revenue of $8.5 billion for FY2025.
US Headquarters: Chicago, IL Employees: ~15,000 (US), 73,000 (global) Key Services: Business Consulting, Data Analysis, Lease Accounting, Audit, Tax
Grant Thornton has carved out a strong reputation for business consulting, data analysis, and lease accounting. The firm is consistently cited for its collaborative company culture and competitive employee benefits — factors that contribute to strong talent retention and high service quality.
Best for: Businesses seeking a mid-sized alternative to the Big 4 with strong advisory capabilities and a collaborative firm culture.
8. CBIZ / Mayer Hoffman McCann (MHM) — The Integrated Business Services Leader
CBIZ, headquartered in Cleveland, Ohio, operates in partnership with Mayer Hoffman McCann P.C. (MHM) to provide integrated accounting, tax, and business advisory services. The combined entity serves clients across a wide range of industries, including software, manufacturing, government, and financial services.
US Headquarters: Cleveland, OH Employees: 6,000+ Key Services: Tax Advisory, Audit, Business Consulting, Financial Management, HR and Benefits
CBIZ/MHM is a notable name on any list of the top 10 accounting firms in America because of its broad reach across 133 US offices and its deep industry specializations.
Best for: Mid-market businesses in manufacturing, government, and financial services looking for comprehensive, locally delivered advisory services.
9. Forvis Mazars — The Fast-Rising National Firm
Forvis Mazars is one of the newest major names in US accounting, formed from the 2022 merger of BKD LLP and Dixon Hughes Goodman (DHG) — and further strengthened through its global combination with Mazars in 2024. The firm now boasts combined revenues exceeding $2 billion in the US and $6 billion globally.
US Headquarters: Springfield, MO Employees: 7,500+ (US) Key Services: Audit, Tax, Advisory, Healthcare, Financial Institutions, Nonprofit
Forvis Mazars is particularly strong in the healthcare, nonprofit, and financial institutions sectors, making it a top choice for specialized industry accounting needs.
Best for: Healthcare organizations, nonprofits, financial institutions, and businesses seeking a fast-growing national firm with deep sector expertise.
10. CliftonLarsonAllen (CLA) — The Collaborative Solution Partner
CliftonLarsonAllen, known as CLA, was founded in 2012 following the merger of Clifton Gunderson LLP and LarsonAllen LLP. With nearly 130 locations across the US and international reach through its global network, CLA has established itself firmly in the top tier of American CPA firms.
US Headquarters: Minneapolis, MN Employees: 8,500+ Key Services: Audit & Assurance, Tax, Outsourcing, Wealth Advisory, Digital Solutions
CLA’s model is built around industry-deep specialization and a philosophy of being a true business partner — not just a compliance vendor. The firm serves clients across industries, including agribusiness, construction, healthcare, nonprofit, and real estate.
Best for: SMBs, nonprofit organizations, real estate firms, and businesses seeking wealth advisory integrated with their accounting practice.
Top Accounting Firms by US City
Top Accounting Firms in New York City (NYC)
New York City is the accounting capital of the United States. The Big 4 — Deloitte, PwC, EY, and KPMG — all maintain their US headquarters in New York. Beyond the Big 4, prominent accounting firms in NYC include:
- Marks Paneth — top regional firm serving real estate and financial services
- EisnerAmper — one of the largest independent advisory and accounting firms in the US
- Mazars USA (now Forvis Mazars) — global firm with strong NYC presence
- Anchin — leading mid-market accounting firm in New York
Top Accounting Firms in Los Angeles, CA
Los Angeles is a major hub for entertainment, real estate, and accounting. Leading accounting firms in Los Angeles include:
- Deloitte, PwC, EY, KPMG (all maintain major LA offices)
- Moss Adams — leading West Coast regional accounting firm
- Marcum LLP — prominent national firm with strong LA presence
- Haskell & White — Southern California specialist
Top Accounting Firms in Chicago, IL
Chicago is home to the US headquarters of several major accounting firms, including RSM, BDO USA, and Grant Thornton. Other notable accounting firms in Chicago include:
- Plante Moran — consistently ranked among the best firms to work for in the US
- Crowe LLP — major national firm headquartered in the Chicago area
- Sikich LLP — technology-focused accounting and advisory firm
Top Accounting Firms in Other US Cities
| City | Notable Firms |
|---|---|
| Washington DC / Maryland | CohnReznick, Thompson Greenspon, Snyder Cohn, Calibre CPA |
| Pittsburgh, PA | Schneider Downs, Smith Elliott Kearns, GRF CPAs |
| Seattle, WA | Moss Adams, Clark Nuber, Sweeney Conrad |
| Minneapolis, MN | CliftonLarsonAllen (HQ), Eide Bailly, Baker Tilly |
Big 4 vs. Mid-Tier Accounting Firms: Which Is Right for You?
Choosing between the Big 4 and a mid-tier firm like RSM, BDO, or Grant Thornton is one of the most consequential decisions a business can make. Here is a direct comparison:
| Factor | Big 4 | Mid-Tier (RSM, BDO, Grant Thornton) |
|---|---|---|
| Best for | Fortune 500, publicly traded | Mid-market, private companies |
| Global reach | 150+ countries | 100+ countries (through networks) |
| Cost | Premium | More competitive |
| Personalization | More standardized | More relationship-focused |
| Industry depth | Broad | Often very deep in specific sectors |
| Technology | Cutting-edge AI/cloud | Strong but less bleeding-edge |
| Regulatory complexity | Excellent for complex compliance | Strong for mid-market compliance |
What Services Do US Accounting Firms Provide?
The modern American accounting firm is far more than a bookkeeping or tax preparation shop. The top firms provide a full spectrum of professional services:
Audit and Assurance: External audits of financial statements, internal audit outsourcing, SOX compliance, and regulatory filings. This remains the bedrock service of every major public accounting firm in the US.
Tax Advisory and Compliance: Federal and state tax preparation, international tax planning, transfer pricing, tax controversy resolution, and R&D tax credits.
Advisory and Consulting: Management consulting, digital transformation, IT risk, cybersecurity, performance improvement, and supply chain optimization.
Deals and Transactions: M&A due diligence, valuation, transaction advisory, restructuring, and post-merger integration.
Outsourced Accounting and CFO Services: Fractional CFO, outsourced controller, bookkeeping, payroll processing, and financial reporting for businesses that need expert finance capability without a full-time hire.
ERP and Technology Implementation: Many top US accounting firms now provide ERP consulting, helping clients implement systems like Odoo, SAP, Oracle, and NetSuite to integrate their accounting, operations, and finance in one unified platform.
How Many Accounting Firms Are in the US?
The United States once had more than 130,000 accounting firms of various sizes. However, this number has declined significantly due to consolidation through mergers and acquisitions, an ongoing accountant shortage, and the rise of technology-driven accounting automation.
Despite fewer firms, the US accounting services industry continues to grow. Total US accounting services revenue has climbed toward $110 billion annually, driven by increasing demand for advisory, consulting, and technology-integrated financial services.
The INSIDE Public Accounting (IPA) 500 ranking — published annually — is the most authoritative source for tracking the top 500 CPA firms in the United States by net revenue.
The Rise of ERP-Integrated Accounting: What It Means for Businesses in 2026
One of the most significant shifts in US accounting is the growing integration of ERP (Enterprise Resource Planning) systems directly with accounting workflows. The top accounting firms have recognized that their clients no longer want siloed finance teams operating separately from operations, procurement, and sales.
Tools like Odoo have become particularly influential for small and mid-sized businesses in the US. Odoo’s open-source ERP platform integrates accounting, invoicing, inventory, CRM, and payroll in a single system, dramatically reducing the manual reconciliation work that traditionally occupied accounting staff.
For businesses evaluating their accounting technology stack, the key questions to ask in 2026 are:
- Is your accounting system integrated with your operational data in real time?
- Are your accounts payable, receivable, and bank reconciliation processes automated?
- Does your ERP platform support multi-company, multi-currency, and consolidated reporting?
- Can your accounting team access live dashboards without waiting for month-end closes?
Businesses that answer “no” to any of these are leaving efficiency — and money — on the table.
💡 Managing your own accounting? See how Odoo replaces disconnected spreadsheets, bookkeeping tools, and siloed software with a single integrated platform built for growing businesses.
How to Choose the Right Accounting Firm for Your Business
Selecting an accounting firm is not just about size or name recognition. The right firm depends on your business’s specific needs, growth stage, and industry. Here is a practical framework:
For large enterprises and publicly traded companies: The Big 4, Deloitte, PwC, EY, or KPMG, remain the gold standard. Their global networks, regulatory expertise, and technology capabilities are unmatched.
For mid-market businesses ($10M–$1B revenue): Consider RSM US (the middle market leader), BDO USA, or Grant Thornton. These firms offer Big 4-quality expertise at more competitive rates with a stronger relationship focus.
For small businesses and startups: Regional firms, local CPA practices, and firms specializing in your industry vertical will deliver better value and more personalized service than the large nationals.
For businesses evaluating ERP and accounting technology: Look for a firm or partner that understands both financial compliance and ERP implementation, as the boundary between accounting and technology has effectively dissolved.
Frequently Asked Questions About US Accounting Firms
What are the Big 4 accounting firms?
The Big 4 accounting firms are Deloitte, PwC (PricewaterhouseCoopers), EY (Ernst & Young), and KPMG. These four firms are the largest professional services networks in the world and dominate the market for auditing publicly traded companies in the United States and globally.
What were the Big 5 and Big 6 accounting firms?
Before 2002, the industry was known as the Big 5, which included the current Big 4 plus Arthur Andersen. Arthur Andersen collapsed following the Enron scandal. Before that, the industry was called the Big 6, with Price Waterhouse and Coopers & Lybrand still operating independently, before merging to form PwC in 1998.
What is the largest accounting firm in the USA?
Deloitte is the largest accounting firm in the United States, with estimated US revenues of approximately $33 billion in fiscal year 2025. Globally, Deloitte generated $70.5 billion in revenue, making it the largest accounting and professional services firm in the world.
What is the difference between an accounting firm and an audit firm?
The terms are often used interchangeably, but there is a distinction. An accounting firm offers a broad range of services, including tax, advisory, bookkeeping, and consulting. An audit firm (or auditing firm) specifically conducts external audits of financial statements to verify their accuracy. Most major accounting firms in the US are also registered audit firms.
Which accounting firms are headquartered in New York City?
Deloitte, PwC, EY, and KPMG all maintain their US headquarters in New York City, making it the undisputed accounting capital of America. Other major firms headquartered in NYC include EisnerAmper and Marks Paneth.
How do I find accounting firms near me in the US?
For local accounting services, start with the AICPA’s CPA locator, the IPA 500 list for regional firms, or search specifically for firms in your city (e.g., “accounting firms in NYC,” “accounting firms in Chicago,” or “CPA firms in Los Angeles”). For ERP-integrated accounting specifically, look for a specialist Odoo or NetSuite implementation partner that combines accounting expertise with technology implementation.
What is a middle-market accounting firm?
A middle-market accounting firm serves businesses that fall between small local clients and Fortune 500 enterprises — typically companies with $10 million to $1 billion in annual revenue. RSM US is the self-described leader in middle-market accounting. BDO USA and Grant Thornton also serve the middle market extensively.
Are the Big 4 accounting firms the best choice for small businesses?
Generally, no. The Big 4 are optimized for large, complex, and publicly traded clients. Small and mid-sized businesses will typically find better value, more responsive service, and more relevant expertise by working with a regional CPA firm or a mid-tier national firm like RSM, BDO, or CLA.
How many people work in accounting in the United States?
The US accounting sector employs approximately 1.4 million accountants and auditors, according to Bureau of Labor Statistics data. The industry is experiencing a notable talent shortage, with demand for qualified CPAs consistently outpacing supply — a trend expected to continue through 2030.
What is the IPA 500?
The IPA 500 is an annual ranking published by INSIDE Public Accounting (IPA) of the top 500 CPA firms in the United States, ranked by net revenue. It is the most comprehensive benchmark for tracking firm size, growth, mergers, and competitive positioning in the US public accounting market.
