Top 20 Accounting Firms in the US: Comprehensive Overview

It will be unfair to assume the top 20 accounting firms in the US are like traditional audit and tax providers. These firms have invested and evolved into technology-driven advisory partners helping practices and businesses navigate compliance, automation, AI adoption, tax planning, and financial growth.

In 2026, many practices are facing rising challenges in the US accounting market. Rising compliance demands, IRS reporting requirements, AI-powered accounting software, staff shortages, and increasing client expectations are reshaping how firms operate.

This brings up a question:

How to maintain profitability, compliance, and service quality in such an environment?

The answer is in the example:

A US CPA firm experienced one of its clients growing well, which increased revenues but also operational pressure. Their staff were getting overwhelmed with bookkeeping reviews, sales tax filings, payroll deadlines, and 1099/W-2 compliance checks. Recruitment costs continued to rise while turnaround times slowed.

Instead of getting stuck with continuous recruitment, the practice chose to explore outsourced bookkeeping services and compliance support. Within months, they experienced workflow efficiency, a reduction in bottlenecks, and the freeing of their experienced staff for advisory work.

The good news is that this scenario is becoming increasingly common across the US accounting sector.

According to the Corporate Finance & Accounting Talent Study 2026, 61% of finance leaders report experiencing either minor or significant shortages of accounting, finance, and CPA talent, a Talent Shortage Index of 77%, driving demand for outsourced compliance and specialized finance expertise.

In this guide, we’ll explore:

• What makes an accounting firm top-tier in 2026
• The top 20 accounting firms in the US
• Services offered by leading firms
• Emerging industry trends
• How outsourcing is helping firms scale efficiently

What Makes a US Accounting Firm Top-Tier in 2026

Revenue is not the only aspect that makes an accounting firm rank among the US’s leading accounting practices. There are many reasons that propel an accounting firm toward the Top 20 accounting firms in the US.

Let’s understand those factors.

Technical Expertise

The top 20 accounting firms in the US have been able to maintain their position through continuous investment in furthering their technical capabilities, like:

• Audit planning
• Tax advisory
• Corporate finance
• Outsourcing
• Business consulting
• Compliance services

To survive in the competitive US accounting environment, clients are increasingly depending on strategic advice from you instead of basic bookkeeping support and technical expertise alone.

Technology Adoption

To stay relevant against evolving IRS e-filing requirements, state-level sales tax complexity, and stricter regulatory enforcement, modern accounting practices are increasingly focusing on:

• Cloud accounting systems
• AI-powered automation
• Digital audit tools
• Workflow management platforms
• Real-time reporting dashboards

These technologies improve accuracy and efficiency while reducing manual workloads.

Industry Specialization

You will find multiple accounting firms that have developed expertise in specific sectors such as:

• Construction
• Healthcare
• E-commerce
• Staffing and recruitment
• Real Estate
• Manufacturing
• Technology

Such sector-specific expertise allows them to provide more tailored solutions.

Scalability

The top 20 accounting firms in the US have ensured they can scale their services without compromising on quality. They have achieved that through:

• Standardized workflows
• Automation platforms

Client Experience

Top 20 accounting firms in the US place greater attention on what their clients say and expect from them. That’s why they place special emphasis on:

• Faster response times
• Proactive communication
• Transparent reporting
• Advisory-led relationships

In 2026, clients increasingly value firms that listen and address their concerns quickly and provide insights beyond compliance alone.

Overview of Top 20 Accounting Firms in the US

You will find yourself surrounded by multiple outsourced accounting firms in the US these days, but only a select few can be considered the best. Here is the list of the top 20 accounting firms in the US:

1. Corient Business Solutions

Corient Business Solutions has become a trusted outsourcing partner for US accounting practices and CPA firms looking to scale without increasing fixed overheads. It has made its name for providing US CPA firms with reliable outsourced accounting and bookkeeping along with payroll, tax preparation support, management accounts, financial reporting & analysis, CFO and business advisory services, and finance back-office support.

With a strong presence in the US market and an additional office in Coventry, UK, Corient combines global reach with consistent, dependable service, making it a standout choice for firms looking to streamline operations and focus on growth.

Corient also gives top priority to data security by having:

• ISO 27001 certification
• Being fully compliant with US data protection and confidentiality standards
• Multi-factor authentication and end-to-end encryption
• Cyber Essentials certification

Best for: US CPA firms and accounting practices seeking scalable outsourcing support, payroll processing, bookkeeping, and compliance services.

2. Deloitte

Deloitte is the largest accounting firm in the US and the world by both revenue and headcount, offering audit, tax, risk advisory, and consulting services to the largest multinational corporations.

Best for: Large corporations and multinational enterprises needing external audit and advisory at scale.

3. PwC

PwC commands one of the largest audit practices among the Big Four, serving a majority of Fortune 500 companies with audit, tax, deals, and digital transformation advisory.

Best for: Large corporations requiring external audit services and M&A advisory.

4. EY

EY emphasizes innovation, sustainability, and entrepreneurship, making it a strong fit for growing and rapidly changing organizations across audit, tax, and consulting.

Best for: Growing enterprises and organizations undergoing digital or ESG transformation.

5. KPMG

The smaller of the Big Four by US revenue, KPMG is strong in audit and advisory, particularly for regulated industries such as financial services, energy, and infrastructure.

Best for: Regulated industries needing specialized audit and advisory expertise.

6. RSM US LLP

RSM is the largest firm outside the Big Four in the US, focused on middle-market businesses that have outgrown a local CPA firm but don’t need Big Four scale.

Best for: Middle-market businesses in manufacturing, real estate, healthcare, and technology.

7. BDO USA

BDO offers a strong hybrid of national scale and personalized service, with particular strength in retail, nonprofit, and financial services clients.

Best for: Mid-sized businesses wanting a balance of scale and customization.

8. Grant Thornton LLP

Grant Thornton offers national scale, broad advisory capability, and international connectivity while remaining more accessible than the largest firms.

Best for: Private companies and nonprofits wanting senior-level attention without a large-firm account structure.

9. Forvis Mazars

Formed through the BKD–Dixon Hughes Goodman merger and its later combination with Mazars, Forvis Mazars ranks among the US top 10 firms, offering assurance, tax, and consulting services.
Best for: Mid-market and growth-stage businesses needing full-service assurance and tax support.

10. CBIZ

CBIZ, now combined with its attest partner Mayer Hoffman McCann and having absorbed Marcum, is a top-tier national provider of accounting, tax, and advisory services.

Best for: Businesses seeking integrated accounting, benefits, and advisory services under one roof.

11. Baker Tilly

Baker Tilly has grown rapidly through acquisitions and offers audit, tax, and advisory services with increasing investment in AI-driven capabilities.

Best for: Growing businesses and organizations across a broad range of industries.

12. Crowe LLP

Crowe is a leading audit, tax, advisory, and consulting firm offering specialist services in assurance, corporate tax, and risk consulting.

Best for: Businesses across a wide range of sectors needing audit and consulting expertise.

13. Moss Adams

Moss Adams is known for deep industry specialization and a strong West Coast presence, serving middle-market and privately held businesses.

Best for: Privately held and middle-market businesses, particularly on the West Coast.

14. CohnReznick

CohnReznick offers assurance, tax, and advisory services with particular strength in real estate, technology, and government contracting.

Best for: Real estate, technology, and government-contracting businesses.

15. Plante Moran

Plante Moran is consistently ranked among the best firms to work for and offers a full range of audit, tax, and consulting services with a strong Midwest presence.

Best for: Privately held businesses and nonprofits seeking a full-service regional partner.

16. PKF O’Connor Davies

PKF O’Connor Davies has grown into a top-tier national firm, offering audit, tax, and advisory services with particular strength in nonprofit and employee benefit plan audits.

Best for: Nonprofits, healthcare organizations, and employee benefit plan sponsors.

17. Withum

Withum combines national scale with an entrepreneurial, tech-forward culture, offering assurance, tax, and advisory services across multiple industries.

Best for: Tech-forward businesses and startups needing scalable advisory support.

18. Eide Bailly

Eide Bailly is a top-tier regional firm with strength across the central US, offering audit, tax, and consulting services to a broad range of industries.

Best for: Businesses across the central US seeking full-service regional support.

19. Wipfli

Wipfli offers accounting, tax, and consulting services with a strong focus on technology-enabled advisory and industry-specific solutions.

Best for: Businesses seeking technology-enabled advisory and outsourced accounting support.

20. Cherry Bekaert

Cherry Bekaert is a fast-growing national firm offering assurance, tax, and advisory services with strength in government contracting, manufacturing, and private equity-backed businesses.

Best for: Private equity-backed businesses and government contractors.

Top 20 US Accounting Firms Comparison Table

Firm	Best For	Key Strength
Corient Business Solutions	US CPA & Accounting Practices	Outsourced Accounting & Compliance Support
Deloitte	Large Corporations	Audit, Tax & Consulting at Scale
PwC	Fortune 500 Companies	Audit & M&A Advisory
EY	Growing Enterprises	Innovation & ESG Advisory
KPMG	Regulated Industries	Audit & Regulatory Advisory
RSM US LLP	Middle-Market Businesses	Audit & Tax for Mid-Market
BDO USA	Mid-Sized Businesses	Scale + Personalized Service
Grant Thornton LLP	Private Companies & Nonprofits	National Scale, Accessible Service
Forvis Mazars	Mid-Market & Growth Businesses	Assurance, Tax & Consulting
CBIZ	Integrated Advisory Needs	Accounting, Benefits & Advisory
Baker Tilly	Growing Businesses	Audit, Tax & AI-Driven Advisory
Crowe LLP	Multi-Sector Businesses	Audit, Tax & Risk Consulting
Moss Adams	Privately Held Businesses	Industry Specialization
CohnReznick	Real Estate & Tech	Assurance & Advisory
Plante Moran	Nonprofits & Private Businesses	Full-Service Regional Partner
PKF O’Connor Davies	Nonprofits & Healthcare	Nonprofit & EBP Audits
Withum	Tech-Forward Businesses	Entrepreneurial Advisory
Eide Bailly	Central US Businesses	Full-Service Regional Support
Wipfli	Tech-Enabled Advisory Needs	Outsourced Accounting Support
Cherry Bekaert	PE-Backed & Government Contractors	Assurance & Advisory

Services Offered by Top US Accounting Firms

Leading top 20 accounting firms in the US are already offering more than just traditional accounting services.

Audit and Assurance

Under it, the services include:

• Financial statement audits
• Internal audits
• Risk assessments
• Regulatory compliance reviews

Tax Advisory

Accounting firms have started assisting practices in giving tax insights through services like:

• Corporate tax
• State and local tax (SALT) planning
• International tax
• R&D tax credits
• Capital gains tax

Bookkeeping and Outsourcing

Multiple practices are now comfortable outsourcing:

• Bookkeeping
• Payroll
• Accounts payable
• Accounts receivable
• Management accounts

Through the outsourcing of these tasks, you can scale efficiently while reducing staffing pressures.

Payroll Services

Growing payroll compliance requirements have made this more complex, making payroll outsourcing increasingly attractive.

Services under it often include:

• Federal and state payroll tax processing
• 401(k) and benefits administration
• W-2/1099 compliance
• Multi-state payroll reporting

Advisory Services

Accounting firms at the top are increasingly placing special focus on meeting their clients’ high-end advisory requirements through:

• Cash flow planning
• Business strategy
• Mergers and acquisitions
• Financial forecasting
• Digital transformation

This shift toward advisory work is improving profitability across the industry.

Trends Impacting US Accounting Firms in 2026

The US accounting sector is going through some remarkable transformations. Some of those are:

AI-Powered Accounting

Artificial intelligence has enabled practices to automate:

• Invoice processing
• Data entry
• Reconciliations
• Fraud detection
• Financial reporting

Practices that have invested in training teams and operating AI in accounting and finance workflows have been able to reduce operational costs considerably. In the future, AI will increasingly influence traditional accounting workflows.

Growing Demand for Outsourcing

Due to rising compliance requirements and a persistent talent shortage, many practices are facing:

• Recruitment challenges
• Rising salary costs
• Increased compliance workloads

Outsourcing has assisted practices in reducing workload pressure without expanding internal headcount. That’s why practices are increasingly partnering with specialist providers like Corient Business Solutions for:

• White-label Bookkeeping
• Sales tax support
• Payroll processing
• Year-end reporting preparation
• Audit support

IRS Digital Reporting Requirements

Digital reporting expectations continue to expand and influence accounting workflows.

Practices must maintain:

• Digital records
• Automated reporting systems
• IRS e-filing-compatible software

This creates ongoing demand for cloud accounting expertise.

Private Equity Investment

Private equity continues to reshape the accounting sector.

Many firms are seeking investment to fund:

• Technology upgrades
• Acquisitions
• Talent acquisition
• Geographic expansion

This trend is particularly visible among mid-market firms such as CBIZ and Baker Tilly.

Cloud Accounting Growth

You cannot do your job without using the right accounting tools, like:

• QuickBooks
• Xero
• Sage

These are the tools driving digital transformation.

Through these cloud systems, you will see an improvement in:

• Collaboration
• Reporting visibility
• Compliance management
• Workflow efficiency

People Also Ask:

Conclusion

The Top 20 accounting firms in the US are not a constant list, they will keep on evolving, and it requires more than compliance expertise to stay on this list.

The firms leading the market are investing in:

• Technology
• Automation
• Cloud accounting
• Outsourcing
• Advisory services

At the same time, practices of all sizes face increasing pressure from compliance demands, talent shortages, and growing client expectations.

This is why scalable support models are becoming essential.

By combining internal expertise with outsourcing partners such as Corient Business Solutions, US accounting practices can increase capacity, improve efficiency, and focus on delivering higher-value advisory services without overwhelming their teams.

The future of US accounting belongs to firms that can balance technology, people, and operational scalability, and those firms are already building that advantage today. Corient Business Solutions ticks all the above boxes. Want to do everything right in accounting outsourcing? Contact us and see it for yourself.