What Thompson Greenspon does

Thompson Greenspon is a privately held, full-service CPA firm founded in 1956 and headquartered in Fairfax, Virginia, providing tax planning and preparation, financial reporting and assurance, advisory, client accounting and advisory services (CAAS), and employee benefits plan audits. The firm serves four industry verticals with deep specialization: Construction & Real Estate, Government Contracting (including FAR compliance, overhead rate audits, and SF 1408 pre-award surveys), Nonprofit organizations (including Single Audits and Form 990 preparation), and Professional Services firms. It is recognized as a Top 40 firm in the Metro DC area and a Top 400 firm nationally by Inside Public Accounting, and is described as one of the largest CPA firms headquartered in Virginia.

The firm's business model is relationship-driven professional services delivery, with revenue generated from project- and annual-retainer-based engagements across tax, audit, and advisory lines. Pricing is quote-based and not publicly disclosed, consistent with custom professional services engagements. Approximately 60–70 team members serve clients, of whom roughly 70% of professional staff are experienced CPAs — a substantially higher concentration than at Big 4 firms. The firm maintains an international affiliation with CPAmerica/Crowe Global, providing access to cross-border advisory resources while preserving local independence. Technology stack consists of standard accounting and tax preparation software, supplemented by third-party workflow tools (ShareFile, Suralink, RightSignature) for client document management and e-signature; no proprietary platform or AI/ML products are indicated. The firm explicitly positions itself as "proudly independent" amid ongoing industry consolidation and PE investment in the accounting sector.

Geographically, Thompson Greenspon operates a single office in Fairfax, Virginia, serving clients across the Washington, DC Metro area. The firm has announced an office relocation in September 2026 to 4100 Monument Corner Drive, signaling facility investment and headcount growth planning. Distribution is direct: enterprise and SMB clients engage through personal consultations, the firm's website, and referral-based business development, supplemented by an active content marketing program (blog, industry thought leadership, email newsletters) and community engagement (34+ local nonprofits supported).

Name

Thompson Greenspon

Legal name

Thompson Greenspon

Website

https://tgccpa.com

Company type

Private

Founded year

1956

Operating status

Operating

Headcount range

101–250 employees

Short description

Thompson Greenspon is a privately held Fairfax, Virginia-based CPA firm founded in 1956 providing tax, audit, advisory, and client accounting services with deep specialization in Construction & Real Estate, Government Contracting, Nonprofit, and Professional Services verticals across the Metro DC area.

Ownership category

akta.pro rank

Product category

Accounting & Advisory Services

NAICS

Offices of Certified Public Accountants (541211), Other Accounting Services (541219)

akta.pro primary industry

Financial Reporting & Technical Accounting Advisory (GAAP/IFRS) (BPAHABAF)

Keywords

• Cpa services
• Tax planning
• Audit assurance
• Business advisory
• Government contracting accounting

Headquarters

HQ city

Fairfax

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

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

Revenue model

1. Professional Services Fees: Revenue generated from providing tax services, financial reporting and assurance, advisory services, client accounting and advisory services (CAAS), and employee benefits planning and audits. Primarily annual recurring engagements with professional service billing.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels3 records

Core offering

Thompson Greenspon is a full-service CPA firm providing tax planning and preparation, financial reporting and assurance, business advisory, client accounting and advisory services (CAAS), and employee benefit plan audits. Services are delivered primarily to businesses in four specialized verticals — Construction & Real Estate, Government Contracting, Nonprofit, and Professional Services — with additional individual tax and wealth planning services.

Product overview

Thompson Greenspon is a full-service CPA firm offering a unified portfolio of professional services rather than a software product platform. The core service offerings include Tax Services, Financial Reporting & Assurance, Advisory Services, Client Accounting & Advisory Services (CAAS), and Employee Benefits Planning and Audits. These services are delivered across four specialized industry verticals: Construction & Real Estate, Government Contracting, Nonprofit, and Professional Services. The firm serves clients from its Virginia headquarters, providing both industry-specific expertise and comprehensive accounting/tax/advisory capabilities as an integrated professional services practice.

Differentiator

Problem solved

Functional benefit

Products and services

• Tax Services Comprehensive tax planning and preparation services including income taxes, trust and estate taxation, payroll tax, tax planning, IRS representation, estate planning, R&D tax credits, and cost segregation studies for businesses and individuals.
• Financial Reporting & Assurance Wide range of assurance services including audits, reviews, compilations, overhead rate audits and FAR compliance, bank financing assistance, internal controls evaluation, lease accounting standards compliance, and SF 1408 pre-award survey audits for businesses.
• Advisory Services Business advisory services including new business formation, strategic business planning, succession planning, mergers and acquisitions support, Employee Retention Tax Credit assistance, and PPP Loan assistance for business owners and management teams.
• Client Accounting & Advisory Services (CAAS) Outsourced accounting and advisory services allowing clients to focus on business goals while Thompson Greenspon handles bookkeeping, payroll, taxes, and financial reporting.
• Employee Benefits Planning and Audits Employee benefit plan guidance and audit services to help organizations ensure they have compliant benefit plans meeting regulatory requirements.
• Construction & Real Estate Industry Services Specialized accounting, tax, and advisory services for construction companies and real estate businesses, leveraging over 70 years of industry expertise including job costing and contract compliance.
• Government Contracting Industry Services Specialized accounting, tax, and advisory services for government contractors including overhead rate audits, FAR compliance, and SF 1408 pre-award surveys.
• Nonprofit Industry Services Comprehensive services for nonprofit organizations including audits, Form 990 preparation, Single Audits under Uniform Guidance, and advisory services.
• Professional Services Industry Services Accounting, tax, and advisory services tailored for professional services firms including law firms, consulting practices, and other service businesses.

Segments4 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration3 records

Partnerships

One partnership is on record.

• CPAmerica/Crowe GlobalcoreStrategic or Co-development PartnerInternational affiliation with CPAmerica/Crowe Global network providing Thompson Greenspon clients access to experienced business advisors around the world while maintaining local expertise and personal service.

Scale indicators3 records

Recent moves7 records

Expansion highlights4 records

Broad incumbents

• Cherry Bekaert: Large Southeast/Mid-Atlantic CPA and advisory firm with deep government contracting and construction practices; broader scale and footprint than Thompson Greenspon.
• CohnReznick: National CPA and advisory firm with strong government, construction, and real estate practices; overlapping specializations but far larger scale.
• CliftonLarsonAllen (CLA): Top-10 national professional services firm offering tax, audit, and outsourced accounting to construction, nonprofit, and government-contractor clients, competing for the same engagements at national scale.
• Forvis Mazars: Large national accounting and advisory firm with government contracting and construction practices; overlapping capabilities but part of a much wider, consolidated platform.

Regional players

• Kearney & Company: Alexandria, VA CPA firm specializing in federal government audit and financial services, overlapping Thompson Greenspon's government contracting/compliance niche in the DC metro.
• YHB CPAs & Consultants: Virginia-based independent CPA firm offering tax, assurance, and advisory services to similar business and nonprofit clients across the state.
• PBMares: Virginia-headquartered top-tier CPA and advisory firm serving construction, government contracting, and nonprofit clients — nearly identical service and vertical mix in the same region.

Direct peers

• Aronson LLC: Rockville, MD CPA firm long known for government contracting, construction, and nonprofit accounting and advisory in the DC metro — a close competitor across the same verticals.
• Halt, Buzas & Powell: Alexandria, VA independent CPA firm providing tax, audit, and advisory services with a government-contracting and nonprofit focus, closely comparable in size and market.
• Councilor, Buchanan & Mitchell (CBM): DC-area independent CPA firm offering tax, audit, and advisory services to construction, nonprofit, and government-contractor clients, directly overlapping Thompson Greenspon's market and offering.

Market position

Strengths5 records

Weaknesses4 records

Competitive moat5 records

Key risks5 records

Key highlights6 records

Customer concentration

• Xx.com/tgccpa
• Facebookfacebook.com/tgccpa

Compliance2 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles10 records

Funding overview

Funding rounds

Investors

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 Thompson Greenspon