Who Should Prepare Your Cost Segregation Study? The IRS 'Expertise and Experience' Element, Explained

The Short Answer

Your cost segregation study should be prepared by someone who knows how buildings are constructed, has experience estimating and allocating construction costs, and understands the tax law that decides which components are personal property, land improvements or structure. That is a paraphrase of what the IRS itself says. Its Cost Segregation Audit Techniques Guide (Publication 5653, Chapter 4) lists "Preparation by an Individual with Expertise and Experience" as the first element of a quality study.

The IRS does not name a license, a degree or a title. For years that left owners and CPAs with no neutral way to check a preparer's qualifications beyond the firm's own description. That has changed. The National Board of Cost Segregation Specialist (NBCSS) now publishes a standard for the discipline, assesses practitioners against it through the Certified Cost Segregation Specialist (CCSS) credential, and maintains a public directory. This article explains the IRS element, what it means in practice, how the NBCSS assessment maps onto it, and how to look a preparer up before you hire.

For disclosure: every Caliber Cost Segregation Professional is CCSS-certified by the National Board of Cost Segregation Specialist (NBCSS), and Caliber is an NBCSS member.

What the IRS Audit Techniques Guide Says

The Audit Techniques Guide is the manual IRS examiners use when they review a cost segregation study. Chapter 4 sets out the elements of a quality study, and the first one listed is "Preparation by an Individual with Expertise and Experience." The guide goes on to describe what that means in substance: knowledge of the construction process, experience in cost estimating and allocation, and command of the tax law of property classification.

Two things about this are worth noticing. First, the IRS puts the preparer ahead of the method. Before it discusses how a study should be documented or reconciled, it asks who did it. Second, the guide deliberately describes competencies rather than credentials. It does not say the preparer must hold any particular license, degree or professional designation. It prescribes no license and no title. A quality study can be prepared by anyone who actually has the three competencies, and a poor one can be prepared by anyone who lacks them, whatever their letters.

That makes the element both sensible and hard to apply. An examiner can judge expertise from the work in front of them. An owner choosing a provider has to judge it in advance.

What Expertise and Experience Means in Practice

The three competencies the IRS describes correspond to three things a study has to get right.

Knowledge of the construction process is what lets a preparer identify components correctly. A building is a set of systems: structure, envelope, electrical, plumbing, mechanical, finishes, site work. Someone who understands how those systems are assembled can tell which parts of an electrical system serve the building as a whole and which serve specific equipment, or whether a floor finish is glued down or part of the structural slab. Those distinctions decide classification.

Experience in cost estimating and allocation is what lets a preparer put defensible numbers on those components. A study that says the five-year property is worth a certain amount needs quantities behind it, unit costs from a published source, and an allocation method that reconciles to the actual basis without double-counting. This is the half of the work that is most often done by rule of thumb, and rules of thumb are what examiners look for.

Command of the tax law of property classification is what lets a preparer decide, and justify, which depreciation life each component belongs in. The authorities are case law, revenue procedures and the guide itself, and they are not always intuitive. Two similar items can land in different classes depending on function and attachment.

A preparer who has only one or two of these will produce a study with a characteristic weakness: a tax professional without construction knowledge misidentifies components, an estimator without tax knowledge misclassifies them, and anyone without allocation experience produces totals that do not reconcile.

Why a Published Standard Changes the Question

Until recently, asking a provider "does your preparer have expertise and experience?" produced an answer you could not check. Firms described their teams in their own words, and an owner had no independent reference point.

A published standard changes that in two ways. First, it defines the competencies concretely. The NBCSS standards set out what a Certified Cost Segregation Specialist must demonstrate, so an owner or CPA can read the definition rather than accept a firm's. Second, it separates the claim from the proof. The NBCSS repeats one principle across its site: membership is admission to the organization, and certification is a separate, assessed decision. Payment, membership approval and course completion never award the CCSS credential.

The standard also defines experience in a way that can be verified. One route to eligibility for the credential requires two years of practice and ten personally performed studies, evidenced by two authorized, client-redacted sample reports plus work-history hours. The other route runs through a 14-course Practitioner Program of about 140 hours. Either way, eligibility is a reviewed status, not a self-description.

It is fair to note the scheme's limits. The current CCSS scope is residential, and the scheme was adopted on September 24, 2026, with interim cut scores pending pilot standard-setting. The board says so plainly. A new standard honestly labelled is still a great deal more than no standard at all.

How the NBCSS Assessment Maps to the IRS Element

The CCSS assessment has four parts, and the first three line up with the three competencies the IRS describes.

The knowledge examination is a timed 180-minute test with a 70 percent interim passing standard. This is where command of the tax law of property classification and the fundamentals of construction and depreciation are tested as knowledge.

The practical case exercise runs six to eight hours. All deterministic checks must pass, and the candidate must score at least 3 of 4 on every rubric criterion. This is the direct test of experience in cost estimating and allocation. A candidate has to take a property, identify and quantify its components, cost them, allocate the basis and produce a study whose arithmetic reconciles. It is not possible to pass this part on rules of thumb, because the deterministic checks exist to catch exactly that.

The oral defense is a 30-minute examination before two examiners. This is the part most relevant to an owner, because it rehearses the situation you are paying to be prepared for: a knowledgeable questioner asking the preparer to justify a classification. A preparer who has defended a study to two examiners has done, in a controlled setting, what they would do for you in an examination.

The fourth part is a human decision-maker review. Automated scoring assists the process but never adjudicates. After certification, credential holders complete 12 hours of professional development in each 12-month cycle, recorded on the platform, which the board describes as an internal NBCSS requirement and not CPE credit.

How to Look Someone Up

The practical payoff of a published standard is that you can check it. The NBCSS directory lists current Professional Members and Organization Members who have opted in. You can search by ZIP code, city or state with a radius, and filter by study type (acquisitions, lookback studies, new construction, renovations, dispositions and pre-purchase estimates), by property type, by language and by coverage area. Listings can also be browsed by state and city.

When you look a firm or person up, pay attention to which status is shown. "Professional Member" and "Certified" are separate, verified statuses. A firm can be an Organization Member without any individual holding the CCSS credential. The credential itself is publicly verifiable, and any change in standing is shown immediately, so a current listing reflects current status.

Read the board's own cautions as well. A directory listing is not a promise of leads or employment, self-reported statements are labelled as such, and a listing is not a recommendation. The directory tells you what has been verified and what has not. It does not choose a provider for you.

If your CPA is involved in the decision, the board also runs partner directories for accountants and tax strategists and for real estate professionals, in which the board verifies the license or credential shown and displays the date it was checked.

Questions to Ask Any Provider

Whether or not a provider is an NBCSS member, the IRS element gives you a short list of questions.

A provider with real expertise and experience will find these questions easy. At Caliber, every study is Signed & Certified by a Cost Segregation Professional, the unit costs are tied to published construction cost references, and the report shows the component-level work. You can see what that looks like in our sample report and read how a study moves from documents to signature on our how it works page. Studies start at $3,995.

What to Do Next

Before you engage anyone, look the preparer up in the NBCSS directory and confirm which status is shown. Then ask the questions above. If you would like to see how Caliber answers them in a finished report, our sample report shows the component inventory, the cost citations and the signature page.