A cost segregation study breaks a building into components such as land improvements, fixtures and personal property, so parts of the cost can be depreciated over 5, 7 or 15 years instead of 27.5 or 39. For property owners, that can move significant tax deductions into the early years of ownership, especially when bonus depreciation applies. This list is for real estate investors, developers and their CPAs choosing a cost segregation provider in 2026.
We reviewed each firm’s website for its study methodology, use of engineers, property types served, audit support and related tax services. Rankings reflect that review, not payment. This list is not tax advice; confirm the right approach with your own tax adviser.
Top Cost Segregation Firms To Hire
| Firm | Best For | Related Services |
|---|---|---|
| Engineered Tax Services | Owners wanting a broad engineering-based tax firm | R&D credits, 179D, 45L |
| Cost Segregation Services Inc (CSSI) | Commercial property owners and CPAs | Fixed asset reviews, 179D |
| KBKG | CPA firms and complex portfolios | R&D credits, 179D, 45L, repair regulations |
| Madison SPECS | Owners wanting large-scale experience | Fixed asset and energy incentives |
| Source Advisors | Mid-market businesses and investors | R&D credits, energy incentives |
| Capstan Tax Strategies | Owners wanting an engineering-led boutique | Fixed asset studies |
| RE Cost Seg | Smaller residential investors | Software-based studies |
1. Engineered Tax Services
Engineered Tax Services is a specialty tax firm based in Florida that performs engineering-based cost segregation studies alongside R&D credits and energy incentives such as 179D and 45L. Its range suits owners and CPAs who want several incentives reviewed together.
Key services: cost segregation, R&D tax credits, 179D and 45L energy incentives, audit support.
2. Cost Segregation Services Inc
Cost Segregation Services Inc (CSSI) is one of the longest-running firms dedicated to cost segregation, working with commercial property owners and the CPAs who advise them. Its studies are engineering-based and built to stand up to IRS review.
Key services: cost segregation studies, fixed asset reviews, 179D, audit defense support.
3. KBKG
KBKG is a tax specialty firm that works closely with CPA firms on cost segregation, fixed asset planning, R&D credits and energy incentives. It also publishes tax tools and guidance used widely by accountants, which makes it a strong partner for complex portfolios.
Key services: cost segregation, repair regulation analysis, R&D credits, 179D, 45L.
4. Madison SPECS
Madison SPECS is a cost segregation and fixed asset firm that has completed studies across many property types for owners, developers and CPA firms. Its scale and experience suit investors with large or varied portfolios.
Key services: cost segregation, fixed asset services, energy incentives, look-back studies.
5. Source Advisors
Source Advisors provides cost segregation studies along with R&D credits and energy incentives for mid-market businesses and real estate investors. Its combined approach helps owners who want all available specialty tax benefits reviewed at once.
Key services: cost segregation, R&D tax credits, energy incentives, tax planning.
6. Capstan Tax Strategies
Capstan Tax Strategies is an engineering-led cost segregation boutique that serves property owners and their advisers. It suits investors who want detailed, site-visit-based studies from a focused specialist.
Key services: cost segregation studies, fixed asset analysis, CPA collaboration.
7. RE Cost Seg
RE Cost Seg offers software-based cost segregation studies aimed at smaller residential and short-term rental investors. It is a lower-cost route for single properties where a full engineering study may not be economical.
Key services: software-based cost segregation studies, residential and short-term rental studies.
One Check Worth Making
Ask how the study will be prepared and documented. The IRS Cost Segregation Audit Techniques Guide favors detailed engineering approaches, and studies with site visits and component-level cost support hold up better under review. Also confirm the provider will work directly with your CPA, since the study only creates value once it is applied correctly on your return.
Conclusion
Engineered Tax Services, CSSI and KBKG are the leading engineering-based providers, Madison SPECS brings scale, and Source Advisors combines cost segregation with other incentives. Capstan Tax Strategies is a focused boutique, and RE Cost Seg suits smaller residential investors.
If you want to add your company to this list, drop us a line or submit a form in the Best Choices section. After a thorough review, we’ll decide whether it’s an appropriate addition.
