Melville, Long Island · New York
Tax, audit and advisory services for closely held businesses, their owners and their families.
For more than thirty-five years, CostaRothbort has helped closely held businesses, their owners and their families make sound financial decisions.
Our partners lead every engagement, from tax planning and multi-state compliance to audits and outsourced accounting, forensic accounting and valuation and succession and estate planning. We serve clients across New York, New Jersey, Connecticut and nationally, and as a BDO Alliance USA member we can draw on national resources while you keep working with the same partner.
Featured industries
High net-worth individuals, families and family offices.
LEARN MORE →Owners, developers, investors, agents and brokers.
LEARN MORE →General, specialty and trade contractors and homebuilders.
LEARN MORE →Local unions, district councils and related organizations.
LEARN MORE →Year-end planning
Many of the most effective tax moves for 2026 must be made before year-end. Talk with a partner now about timing income and deductions, retirement contributions and the New York pass-through entity tax.
Services
Planning, multi-state compliance and IRS and state audit representation.
Audits, reviews and outsourced accounting and CFO services.
Succession, transactions, bonding, financing and estate planning.
Fraud investigations, business valuations and expert testimony.
How we work
Tell us about your business, your goals and any deadlines. A partner meets with you to understand what you need and where we can help.
We put the scope, timing and fees in writing before any work begins, so you know exactly what to expect.
Your partner stays involved all year, not only at filing time, keeping you ahead of deadlines, tax law changes and opportunities.
Practice spotlight
Private client services
We work with high net-worth individuals, families and family offices on tax, estate and wealth transfer planning, coordinating closely with their attorneys, bankers and investment advisors.
Construction and real estate
Construction managers, contractors, homebuilders, developers and property owners rely on us for job costing, bonding support, 1031 exchanges, cost segregation and the financial statements their lenders and sureties need.
Real estate tool
Enter the date you transferred the property you're selling. We'll show the two deadlines that decide whether the exchange qualifies.
Deadlines are calendar days and do not move for weekends or holidays. This tool is for planning only; talk with a partner before you close.
Memberships and affiliations
A study can accelerate depreciation on commercial and residential rental property. Ask a partner whether your property is a good candidate.