Questions to Ask a Cost Segregation Company Before You Hire One

Questions about how the study is actually built

• "Is this an engineering-based study, or a software calculator?" A good answer names the process: site or photo review, construction cost data, and a component-by-component classification, not a one-page output from a depreciation calculator. Engineered vs. software-only cost segregation produces materially different documentation depth.
• "Does my property need a site visit, or can this run from photos?" For a commercial building, expect a site visit or detailed plans. For a short-term rental, a firm built for STR volume should be able to classify from existing listing photos, no inspector required.
• "Will the report follow the IRS Audit Techniques Guide?" The IRS publishes its own guide (Pub 5653) describing what a defensible study looks like. A firm that does not reference it, or does not know what it is, has not built its process around surviving an exam.
• "How many pages is the deliverable, and what's in it?" A real engineered report runs long, commonly 70 pages, because it documents methodology, comparable cost data, and asset-by-asset classification. A two-page summary is not a study; it is a projection.

Questions about pricing and the guarantee

• "What does this cost, and why?" Every legitimate study is custom-priced to the property, since the engineering scope scales with building size and complexity. A firm quoting a flat rate-card price for any building, regardless of size, is not pricing the actual work.
• "Can I see a projected number before I commit?" A firm confident in its own numbers will offer a free estimate before any payment. If the only way to see a number is to pay first, that is worth noting.
• "Is there a guarantee if the study underperforms?" Basis guarantees at least 20 times the fee in first-year deductions on commercial property, or 30 times on a short-term rental, or the study is free. Ask any firm what floor protects you if the numbers come in low.

Questions about who stands behind the work

• "If the IRS questions the study, who defends it?" A firm should offer full audit defense of its own report, meaning the team that built the study answers an examiner's questions about it. That is different from representing the taxpayer overall, which stays the CPA's job.
• "Will you take questions directly from my CPA?" A firm built for collaboration answers the CPA's technical questions on methodology and classifications, not just the owner's. Hesitation here is a sign the firm expects to work in isolation.
• "What happens on a property I have owned for years, versus one I just bought?" A look-back study on an older property gets claimed through Form 3115 with a section 481(a) catch-up in the current year, no amended returns. A newer purchase is more straightforward. A firm should explain the difference without prompting.

Questions that expose a weak provider

• "Can you promise I'll save $X?" A firm answering yes to a specific dollar promise before seeing the property, or before your CPA reviews the full return, is overselling. The honest answer describes the deduction the mechanics can produce, not a guaranteed outcome for you.
• "How fast is turnaround?" "It depends" without a range is a red flag. A real answer sounds like 4 to 6 weeks in peak season, 2 to 3 weeks in January and February.
• "Who actually performs the engineering work?" If the firm gets vague about whether the classification is done in-house, by a named partner, or by an unnamed subcontractor, ask again. You do not need a name, but you do need a straight answer about whether real engineering expertise sits behind the report.

Questions about what happens after the study is delivered

• "What happens if I replace the roof or HVAC next year?" A good answer explains partial asset disposition: the remaining basis of a replaced component can be written off, but only in the tax year of the replacement. A firm that has never mentioned this to you is leaving a real deduction on the table for later.
• "Does the report account for prior renovations, or only the original purchase?" Capital improvements made after purchase carry their own depreciable basis. A thorough firm asks about renovation invoices upfront rather than only classifying the property as it stood at the original closing.
• "What documentation do I actually need to hand over?" A straightforward answer names one or two items: a closing statement or current depreciation schedule, plus improvement invoices if renovations happened. A firm that describes an extensive, open-ended document request is not built around a simple intake process.

A worked example of what a good answer produces

On a delivered free-standing restaurant study, the building basis was $2,804,440. The engineered report identified $599,678 in first-year deductions for a $9,000 fee, a 66.6 to 1 ratio. That number came from a real site review, component-by-component classification (kitchen equipment, decorative fixtures, site utilities), and IRS Audit Techniques Guide aligned documentation. Those are the specifics a good answer to the questions above should produce: a real fee, a real ratio, and a real process behind it, not a rounded estimate from a calculator.

Where to start

Before running through this list with any firm, a free Preliminary Benefit Estimate at /qualify gives you a projected number to compare answers against. If a firm's story does not line up with a number you already have in hand, that mismatch is worth asking about directly. See what a real 70-page report actually contains before you commit to any provider.

None of these questions require a background in tax law to ask, and a firm confident in its own process should welcome all of them. The pattern to watch for is not any single vague answer, it is a cluster of vague answers across pricing, methodology, and turnaround together. One hedge is normal. Three or four in a row is the signal worth acting on.

Frequently asked questions

What is the single most important question to ask a cost segregation company?

Whether the study is engineering-based (site or photo review, construction cost data, IRS Audit Techniques Guide documentation) or a software-only estimate. That answer predicts the depth of everything else: the fee, the deliverable, and how the report holds up under exam.

Should I be worried if a firm won't give a turnaround estimate?

Yes. A firm that regularly runs studies should know its own range, commonly 4 to 6 weeks in peak season and 2 to 3 weeks in January and February. Vague answers here often mean vague answers elsewhere too.

Is a lower fee always a warning sign?

Not by itself, but ask what the lower fee buys. A software-only report can be cheap and thin. What matters is whether the fee produces a defensible, documented study, not just a low number.

Can a cost segregation company guarantee my tax savings?

No firm can honestly promise a specific tax outcome for you, since that depends on your basis, other income, and how the deductions interact with your return. A trustworthy firm describes the deduction and timing the mechanics produce and points the outcome question to your CPA.

Why does it matter whether the firm takes questions from my CPA?

A look-back study's Form 3115 filing and section 481(a) computation require the CPA to trust the methodology behind the numbers. A firm that answers the CPA's technical questions directly builds that trust; a firm that only talks to the owner leaves the CPA guessing.