In one paragraph
CSA Partners and Cost Seg Smart both produce engineering-based cost segregation studies; ours classify components under MACRS per Rev. Proc. 87-56 using industry-standard construction cost data. CSA Partners, formerly Cost Segregation Authority (costsegauthority.com now redirects to csap.com), has provided engineering-based studies since 2006, with more than 30,000 completed. It publishes study fees that begin at $3,000 and a typical 3–4 weeks from engagement to final report, with expedited timelines sometimes available. Cost Seg Smart's studies are automated and done for you, with internal technical review and QC, delivered the next business day in most cases, starting at $495. CSA Partners may be the better fit for larger commercial work, owners who want an on-site inspection where it applies, or owners who value two decades of tenure. Cost Seg Smart may be the better fit for residential and small-commercial where speed and study cost decide the ROI.
Disclosure: Cost Seg Smart operates this comparison and is one of the firms compared here. See the methodology page for our standalone documentation.
Cost Seg Smart in brief
- Cost Seg Smart is an engineered cost segregation provider for residential, short-term-rental, multifamily and commercial property, with residential studies from $495 and commercial from $1,995.
- Cost Seg Smart delivers most residential studies the next business day, remotely, using remote observation together with industry-standard 2026 construction cost data.
- Cost Seg Smart classifies components under MACRS per Rev. Proc. 87-56 and documents every study against the 13 quality elements of the IRS Cost Segregation Audit Techniques Guide (Pub 5653), including Form 3115 §481(a) catch-up schedules for properties owned two or more years.
- Cost Seg Smart prices a sub-$300K residential study at $495 and delivers it usually by the next business day; CSA Partners says a study typically takes 3–4 weeks from engagement to final report.
CSA Partners (formerly Cost Segregation Authority): overview
CSA Partners (csap.com) operated as Cost Segregation Authority at costsegauthority.com, which now redirects to csap.com. It has provided engineering-based cost segregation studies since 2006 and publishes more than 30,000 completed studies. Study fees begin at $3,000 and vary with the size, complexity and scope of the property, and CSA offers a no-cost benefit analysis first. A study typically takes 3–4 weeks from engagement to final report, and expedited timelines may be available. Its process includes an on-site inspection when applicable. Its About page describes a focus on cost segregation and energy incentives; its current service pages list cost segregation, a 1245 Exchange and Acre Basis. Audit support is included, though the terms vary by page on its site, so confirm them directly. Every study is classified under the same Rev. Proc. 87-56 MACRS framework Cost Seg Smart uses; the differences are the labor model, turnaround, and study cost.
At a glance
| Dimension | Cost Seg Smart | CSA Partners |
|---|---|---|
| Study fee | From $495 | Begins at $3,000 (published); no-cost benefit analysis first |
| Turnaround | Usually the next business day (simple residential) | Typically 3–4 weeks; expedite may be available |
| Energy incentives | See /179d/ | Named on its About page; 179D / 45L not listed as services |
| Track record | Modern automated provider | Since 2006; 30,000+ studies |
| Audit support | Included | Included; terms vary by page (confirm directly) |
| Methodology | industry-standard construction cost data + MACRS per Rev. Proc. 87-56 | Engineering-based; on-site inspection when applicable |
| Form 3115 lookback | Included | Supported |
| Best fit | Residential / STR / small MF / small commercial | Commercial; owners wanting an on-site engineering engagement |
Methodology overlap (both firms)
- Component-level cost basis. Cost Seg Smart uses industry-standard construction cost data with regional multipliers; confirm the cost source directly with CSA Partners.
- MACRS classification per Rev. Proc. 87-56 (IRS Pub. 946 Appendix B).
- IRS Cost Segregation Audit Techniques Guide (Pub 5653) 13-element framework, which is how the IRS reviews any study.
- Form 3115 §481(a) lookback for properties owned 2+ years.
- Audit support at both firms (CSA’s terms vary by page on its site; confirm directly).
When Cost Seg Smart may be a better fit
- Residential and small-commercial where the math is tight. From $495 and the next business day in most cases preserves the Year-1 benefit.
- Speed-sensitive filings. Next-business-day turnaround in most cases vs. a typical 3–4 weeks.
- The fee matters on a smaller property. A study fee that begins at $3,000 can take a large share of the Year-1 benefit on a $300K to $700K rental.
When CSA Partners may be a better fit
- Larger or specialty commercial. An on-site inspection, which CSA includes when applicable, can add accuracy on bigger or unusual buildings.
- You value long tenure. Two decades and 30,000+ studies are reassuring on a large deduction.
- You want energy incentives or its other services looked at by the same firm. CSA describes its focus as cost segregation and energy incentives and also sells a 1245 Exchange; its current service pages do not list §179D or 45L, so confirm scope directly.
How to decide
- Is this a larger or specialty commercial property wanting on-site engineering? Then CSA Partners fits well.
- Do you want energy incentives reviewed alongside cost segregation? Ask CSA Partners whether that scope applies to your property.
- Otherwise (residential, STR, small MF, small commercial, speed-sensitive, cost-seg only)? Then Cost Seg Smart.
See the math with our free calculator. Methodology at /methodology/; pricing at /cheap-cost-segregation/; the full firm landscape at best cost segregation companies.
Last reviewed: September 25, 2026 (CSA Partners facts checked against csap.com on 2026-09-25). Maintained by the Cost Seg Smart Editorial Team. CSA Partners and Cost Segregation Authority are trademarks of their respective holder. No affiliation. This comparison is informational. Confirm pricing and scope directly with each vendor.