The 30-second answer
There is no single best cost segregation company, only the best fit for your property. Every reputable firm uses the same core methodology, industry-standard construction cost data and MACRS classification per Rev. Proc. 87-56, addressed to the IRS Cost Segregation Audit Techniques Guide. What differs is price, turnaround, and labor model. Large engineering firms (KBKG, CSSI, ETS, Capstan, Bedford) fit $5M+ commercial, hospitality, and unusual properties where on-site engineering judgment earns its fee. Automated providers like Cost Seg Smart fit residential, STR, small multifamily, and small commercial, where speed and study cost decide the ROI.
Disclosure: Cost Seg Smart operates this page and is one of the firms compared here. We have tried to describe each firm by best-fit segment rather than rank them; confirm current pricing and scope directly with each vendor.
How to choose: the criteria that matter
- Methodology. Any firm worth hiring uses construction-cost-data component pricing and Rev. Proc. 87-56 MACRS lives, documented against IRS Pub 5653. This is table stakes; it is not a differentiator.
- Property fit. Match the firm's model to your asset. A $5M hotel and a $400K STR are different problems.
- Price vs. benefit. A $5,000 fee is trivial on a $5M property and ruinous to the ROI on a $400K one. Make sure the study fee does not eat the Year-1 benefit.
- Turnaround. If your return is in extension, weeks versus an hour can be the deciding factor.
- Audit support. Confirm the firm stands behind the report if the IRS asks questions.
The firms at a glance
| Firm | Study fee | Turnaround | Best fit |
|---|---|---|---|
| Cost Seg Smart | From $495 | Under 1 hour | Residential, STR, small MF, small commercial |
| KBKG | ~$5,000+ residential | 4 to 6 weeks | $5M+ commercial, hospitality, REIT |
| CSSI | Quoted | ~6 weeks | Commercial; local-rep relationship |
| Engineered Tax Services | Quoted | Multi-week | Commercial; bundles R&D / §179D |
| Cost Segregation Authority | Quoted | Multi-week | Commercial; bundles energy incentives |
| Maven | Quoted | ~3 to 4 weeks | Engineer + CPA pairing; condensed or on-site |
| Cost Segregation Guys | Flat fee, quoted | Multi-week | Commercial; accountant-coordinated |
| Madison SPECS | Quoted | Multi-week | High-end commercial / industrial |
Competitor fees are quoted per property and not published as fixed tables; the values above are directional, confirm current pricing and scope directly with each vendor. KBKG's residential figure is the firm's commonly cited starting range.
When a large engineering firm is the right call
For commercial property over roughly $5M, hospitality, large multifamily, ground-up construction, or buildings with significant specialty assets, the established engineering firms (KBKG, CSSI, Engineered Tax Services, Capstan, Bedford, Madison SPECS) earn their fee. At that scale the study cost is a rounding error against the deduction, and on-site engineering judgment can materially affect the schedule. If you also want energy incentives like §179D bundled, firms such as Cost Segregation Authority and ETS handle both.
When an automated provider is the right call
For residential rentals, short-term rentals, small multifamily, and small commercial under about $5M, the math flips. A several-thousand-dollar fee and a multi-week wait can consume the Year-1 benefit on a $400K property. An automated study from Cost Seg Smart uses the same construction-cost data and Rev. Proc. 87-56 classification, delivered in under an hour from $495, with internal technical review and QC and audit support. Same defensible report, a fraction of the cost and time, sized to the property.
A note on "reviews" and rankings
Cost-segregation rankings and review roundups are useful for understanding each firm's model, but treat any single ranking with care, including ours: most are published by firms that compete in the space. The most reliable signal is fit, does the firm's price, turnaround, and labor model match your property? For an independent editorial reference on how firms approach engineering studies, costsegregationreviews.com is a useful starting point.
The bottom line
Pick the firm that fits the property, not the loudest brand. Large engineering firms for large or unusual commercial; an automated provider for residential and small commercial where speed and study cost drive the ROI. To see the Year-1 number on your specific property in 30 seconds, use the free calculator; for the full head-to-head pages, see the comparison hub.