CSSI, Engineered Tax Services, and Cost Segregation Partners are names investors often search when shopping for a cost segregation study. Rather than ranking them, the smart move is to compare any provider on the same criteria: who prepares the study, the method used, report quality, fee structure, audit support, and experience with your property type.
This content is not tax or financial advice for you. Please talk with a CPA to find what's right for your situation.
Who these firms are, in brief
Here's a factual snapshot based on each firm's public materials as of October 2026. Details change, so confirm directly with each firm.
- CSSI (Cost Segregation Services): Describes itself as an engineering-based cost segregation firm working nationwide. Its public materials say it has completed more than 50,000 studies since 2003 and also offers services like the 179D energy deduction and R&D tax credits.
- Engineered Tax Services (ETS): A specialty tax firm founded in 2001 that uses an engineering-based approach to cost segregation. It also offers other specialty tax services, such as R&D credits and energy incentives.
- Cost Segregation Partners: Operates under this name in the cost segregation market. Review its website directly for current details on its team, credentials, and services.
This article isn't affiliated with or endorsed by any of these companies. All names belong to their respective owners.
The comparison checklist
Use this table to compare these firms, or any others, side by side. Fill it in from each firm's proposal and sample report.
| Criteria | What to ask | Firm 1 | Firm 2 | Firm 3 |
|---|---|---|---|---|
| Preparers | Who does the work? Engineers? CCSP credential? | — | — | — |
| Method | Detailed engineering approach? Site visit? | — | — | — |
| Sample report | Includes methods, photos, legal support, reconciliation? | — | — | — |
| Fee | Flat fee? What's included? | — | — | — |
| Audit support | Included? For how long? | — | — | — |
| Form 3115 help | Included for look-back studies? | — | — | — |
| Property experience | How many studies on your property type? | — | — | — |
| Turnaround | Can they meet your filing deadline? | — | — | — |
| CPA coordination | Will they work directly with your CPA? | — | — | — |
How to get apples-to-apples quotes
- Send every firm the same information: purchase price, land value, property type, square footage, placed-in-service date, and any renovation costs.
- Ask for a written estimate of the reclassification and first-year deduction.
- Ask for a sample report for a similar property.
- Compare scope, not just price. A lower fee without a site visit or audit support isn't the same product.
- Share the proposals with your CPA before you sign.
Warning signs with any provider
- A fee based on a percentage of your tax savings
- Guaranteed results before reviewing your property
- Reports that don't name the preparers
- No clear answer on audit support
- Pressure to claim real estate professional status without a real conversation about the rules
Frequently asked questions
Which of these firms is the best?
Should I choose a big national firm?
Do these firms prepare tax returns?
See what your property may qualify for
Run our 2-minute STR Qualification Quiz or model your Low / Mid / High cost segregation range.
Related guides
How to Choose a Cost Segregation Company: 10 Questions to Ask
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Read guideCost Segregation Companies: Engineering Firms vs. CPA Firms vs. Software
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Read guideWhat Cost Segregation Consultants Do (and How to Work with One)
What does a cost segregation consultant actually do? Learn their role, credentials to look for, how they work with your CPA, and how to get the most from one.
Read guideHow Much Does a Cost Segregation Study Cost? 2026 Price Guide
What does a cost segregation study cost? See typical 2026 price ranges by property type, what drives the fee, and how to tell if it pays off.
Read guideThis content is not tax or financial advice for you. Please talk with a CPA to find what's right for your situation.