Cost Segregation Red Flags: What to Watch For Before You Hire Anyone

Why vetting matters even though the method is legitimate

Cost segregation as a method is settled law, following Hospital Corporation of America v. Commissioner (109 T.C. 21, 1997), and the IRS's own Audit Techniques Guide (Pub 5653) describes how a proper study should be done. None of that guarantees any specific firm executes it well. The red flags below are about execution, and they are worth checking on every provider you talk to, not just the ones that seem sketchy on the surface.

Red flag: a number promised before the property is reviewed

A firm that quotes a specific percentage or dollar figure over the phone, before reviewing the building's square footage, construction details, or photos, is not giving you a finding. It is giving you a database average dressed up as a projection. A study typically shifts about 15 to 35% of building basis into faster schedules, and where a given property lands in that range depends on its actual type and construction, a restaurant landing higher, a simple shell landing lower. Anyone quoting a firm number sight unseen is guessing at that variable, not measuring it.

A legitimate estimate still requires basic property information to model. A free Preliminary Benefit Estimate at /qualify works this way: it takes the building's details first, then projects a likely first-year number from those specifics, rather than quoting a figure with nothing behind it.

Red flag: no engineer touching the classification

The IRS's own guide ranks engineering-based methods highest in reliability and cost-estimating or default-percentage approaches lowest. A firm that never has an engineer or trained reviewer look at the specific building, carpet, cabinetry, electrical runs, site paving, is applying a category average. That may be fine for a simple residential property, see where DIY approaches genuinely fit, but it is a meaningful gap on anything more complex, and a firm should be upfront about which approach it is actually using.

Red flag: no workpapers behind the report

A defensible study documents the basis for each reclassified item: what it is, why it qualifies for its class life, how its cost was allocated. A report that hands over a summary number and a total, with nothing showing how that number was built, leaves nothing for your CPA to review and nothing for anyone to point to if a component is later questioned. Ask to see a sample of what the deliverable actually looks like before committing; see what a real engineered report includes for what that documentation should look like in practice.

Red flag: a fee tied to a percentage of savings

Some firms price studies as a percentage of the projected tax benefit rather than a flat, custom-quoted fee. That structure ties the firm's revenue directly to how large a number it reports, which is exactly the wrong incentive on a product whose value is accuracy, not size. See how cost segregation companies actually price their fees for the full comparison. Every study Basis performs is custom-quoted per property based on size and complexity, never as a cut of the projected benefit.

Red flag: vague or absent exam support

Ask any provider a direct question: if the IRS questions a specific component in this study, who answers, and what exactly does that support cover. A vague answer, or one that implies broad representation of you as the taxpayer rather than defense of the report's technical content, is a sign the scope was never actually thought through. See what audit defense of a report actually means for the precise line: Basis's engineering team defends the technical content of the report it produced, and the client's CPA continues to represent the client in the exam and the rest of the return. A firm should be able to state that boundary clearly, not in vague reassurance.

Red flag: the same percentage on every property type

Ask to see a firm's range across different property types. A restaurant, an office, and a medical clinic have different mixes of equipment and site work, and a study typically shifts about 15 to 35% of building basis into faster schedules with real variation by type: real quoted studies have run 24.2:1 on a Medical Clinic, 33.4:1 on an Office/Warehouse, and 66.6:1 on a Free-Standing Restaurant, each landing where it did because of what that specific building actually contains. A firm whose studies all come back at roughly the same percentage regardless of property type is applying a template, not engineering a result, even if it calls the report engineered.

Turn these into questions, including for us

Every one of these red flags converts directly into a question worth asking before you sign anything, of any provider. What information do you need before you can project a number. Who specifically classifies the building's components, and what is their background. What does the deliverable include beyond a summary total. How is the fee structured, and is it tied to the projected benefit in any way. If a component gets questioned on exam, who answers, and what precisely does that cover.

Ask Basis the same five questions you would ask anyone else. The honest answers: a property-specific estimate requires the building's basic details first; classification is done by engineers or trained reviewers, from a site review for commercial property or listing photos for STRs; the deliverable is a full 70-page engineered report aligned to the ATG; every fee is custom-quoted per property, never a percentage of savings; and audit defense covers the report's technical content, with your CPA still representing you throughout.

Getting a real number to compare against

A free Preliminary Benefit Estimate at /qualify gives you a property-specific projection to hold up against whatever another firm quotes you, with nothing charged until you decide to move forward.

Whether a specific firm's answers to these questions satisfy your own risk tolerance is your call to make, ideally with input from your CPA. What these red flags identify is where the actual risk in this industry sits, in execution, not in the underlying method.

Frequently asked questions

Is it a red flag if a firm quotes an exact deduction over the phone?

Yes, generally. A specific dollar figure requires knowing the property's actual square footage, construction, and components. A number given before any of that is reviewed is an assumption, not a finding.

Are percentage-of-savings fees always a scam?

Not necessarily a scam, but the incentive structure is worth weighing carefully: a fee tied to the size of the reported deduction rewards a bigger number regardless of accuracy, which is a meaningful conflict on a product where accuracy is the actual value.

What should a legitimate cost segregation report include?

A defensible report documents each reclassified component individually, what it is, why it qualifies for its class life, and how its cost was allocated, rather than handing over a single summary total with no supporting detail.

How do I know if a firm's audit support claim is legitimate?

Ask what specifically it covers. Legitimate audit support means the firm's engineers answer technical questions about their own report's classifications. Anything implying broader representation of you as the taxpayer oversteps what a study provider is positioned to do.