Here is something most owners do not know. The IRS tells its own examiners how to review a cost segregation study. The playbook is public. It is called the Cost Segregation Audit Techniques Guide, or the ATG.
The ATG describes the principal elements of a quality study. If a report has them, an examiner can follow the work and check it. If a report skips them, the examiner has little to go on, and the numbers are easier to challenge.
What "audit-defensible" means: no one can promise you an audit result, and you should walk away from anyone who does. What we do is name the method in the report, show the support for each part, and stand behind that method in writing.
The elements the IRS looks for
The ATG lists the marks of a quality study. Among the most important:
- Prepared by someone with expertise and experience. The guide says quality depends on who did the work. Cost segregation sits where engineering meets tax law, and the preparer needs both.
- A detailed description of the methodology. The report should explain, step by step, how each part of the building was identified, classified, and priced. An examiner should be able to retrace the path.
- Documentation and photo evidence. The study should show its sources: photos of the property, records, drawings, and cost data. Claims without evidence invite questions.
- Proper legal analysis. Each classification should rest on real authority: the tax code, IRS rulings, and court cases. "We always do it this way" is not a legal basis.
- Reconciliation to your actual costs. The parts in the study must add back up to what you really paid. If the allocated costs do not tie to the purchase records, the whole study is suspect.
An examiner should be able to pick up the report and retrace every number.
How our report maps to each element
We built our report around the ATG on purpose. Here is the element-by-element match:
- Expert preparation, plus a second review. The report names the method it used. Joel Salas, our Director of Tax, signs every study. On an Expert Reviewed study, a professional on our team checks it before he signs.
- Methodology, written out. Your report itemizes 42 distinct parts and explains how each one was identified, classified, and priced. Nothing is a black box.
- Photo evidence, when you send it. The photos you send are matched to each part we find and shown as plates in the report.
- Legal authority, cited. Every report cites our published library of court and IRS authorities, and it keeps growing: code sections, IRS rulings, and Tax Court cases. You can browse the full library yourself.
- Reconciliation, shown. The parts add back to the depreciable basis in the study. The report says where that basis came from.
- Defense in writing. If the IRS examines your study, we defend our work at no extra cost, and the pledge is written down. See exactly what is covered.
What a weak study looks like
Not every study on the market clears this bar. Warning signs are easy to spot once you know the ATG:
- A short report with totals but no part-by-part detail.
- No photos and no record of anyone studying the property.
- No citations to the code, rulings, or court cases.
- Allocations that do not reconcile to what you actually paid.
- No one willing to defend the work if the IRS asks.
A cheap study that cannot answer an examiner's questions can cost far more than it saved. Ask any provider how their report handles each element above before you buy.
Next step: See a sample report to judge the depth for yourself, or see your savings range in seconds for your property.
This guide explains general ideas in plain words. It is not tax advice for your situation, and no study can guarantee an audit outcome. Joel Salas, our Director of Tax, signs every study. Always confirm your plan with your own advisor.