Short answer
A cost segregation report's assumptions and limitations section is where the practitioner tells you what the study rests on and what it does not do. Read it before the asset list. Some limitations are normal and expected: the study is not tax advice, costs were estimated where records were unavailable, the classification of certain items involves judgement. Others are warnings: no site visit was made, the land allocation was assumed, documents were not received, or the report disclaims responsibility for its own numbers. The IRS's Audit Techniques Guide lists the elements a quality study contains, and a limitations section that removes those elements is telling you the study is not one. This article explains how to read the section, what each kind of limitation means, and what to ask about. It is general education, not tax advice.
Why the section exists
A study is an expert's analysis of evidence. Experts state the boundaries of their work so that the reader does not rely on it for something it was never meant to support. The section also protects the practitioner: an examiner who finds an assumption clearly disclosed treats it differently from one that was hidden. A report with no assumptions and limitations section is not a report without limits; it is a report that has not told you what they are.
Limitations that are normal
| Statement | What it means | What to do |
|---|---|---|
| "This study is not tax advice and does not address whether the taxpayer should adopt accelerated depreciation." | The practitioner classifies and costs; the adviser decides | Take the study to your adviser; that is the intended path |
| "Costs for components marked as estimated were derived from take-offs and published unit costs for the location and date." | Records were unavailable for those items and a documented estimate was used, as the IRS guide accepts | Check that the marked items and the unit-cost source are listed |
| "The classification of certain items involves judgement; the legal analysis for each is set out in the report." | The practitioner is telling you where reasonable people might differ | Read those items with your adviser |
| "The study relies on documents provided by the owner, listed in the document index." | Standard reliance | Confirm the index matches what you gave |
| "The study addresses federal income tax classification only." | State conformity is outside scope | Ask your adviser about your state |
| "Passive activity limitations and the taxpayer's ability to use deductions are not addressed." | Correct and honest; those depend on your return | Model them with your adviser before relying on any projection |
Limitations that are warnings
- No site visit. Acceptable for some properties with complete records; a warning otherwise. The report should say why no visit was made and what the effect on reliability is.
- Land allocation assumed. If the land split was taken from a percentage or from an unsupported figure, every later number rests on it. Ask what evidence exists and whether an appraisal or assessor record was considered.
- Documents requested and not received. Normal if disclosed and estimated around; a warning if the missing documents are the closing statement or the construction records for a new building.
- Costs derived from the total. If the limitations say components were "allocated from the purchase price" without take-offs, the study used a rule-of-thumb approach, which the IRS guide treats as the least reliable.
- Preparer not identified. The IRS guide lists identification of the preparer and their credentials among the elements of a quality study. A report signed by a company name only, with a limitation disclaiming individual responsibility, is missing that element.
- "For informational purposes only." A study that disclaims being relied on for tax reporting is not a study you can use for tax reporting. Ask what it is for.
- No reconciliation. If the limitations excuse the absence of a reconciliation to basis, the arithmetic has not been closed.
- Prospective results. Projections of tax savings presented without the passive activity caveat, the recapture caveat and the state caveat.
What a good limitations section still leaves you to do
Even a complete, honest study leaves work for you and your adviser.
- Decide whether to use it. The study does not decide your return position.
- Apply the passive activity rules. Rental losses are generally passive and limited; the study does not know your other income or your participation.
- Handle the mechanics. New acquisition or change in accounting method, elections in or out of bonus depreciation, state adjustments.
- Keep the file. The study, its workpapers and the documents it relied on, for as long as you own the property and after.
- Plan for sale. Recapture and the holding period.
Questions to ask about any limitation
- What is the effect on the reliability of the asset list if this assumption is wrong?
- What would it take to remove the limitation, and what would it cost?
- Is this limitation usual for a property like mine?
- Would you stand behind this classification if it were examined, and is that in the engagement letter?
- Has my adviser read this section?
A practitioner who welcomes those questions has written the section for you. One who treats it as boilerplate has written it for themselves.
Reading the rest of the report through the limitations
Use the section as a lens. Where it says costs were estimated, find those items in the asset list and check that they are marked and sourced. Where it says judgement was involved, find the legal analysis for those items. Where it says documents were not received, check the reconciliation for a residual that might be absorbing the gap. Where it says no site visit was made, look for photographs and ask where they came from. The limitations tell you where the study is weakest; the report should show the practitioner working carefully in exactly those places.
Limitations and the engagement letter
The limitations section and the engagement letter should agree. If the letter promised a site visit and the report says none was made, ask why before you accept the report. If the letter defined the scope as federal classification only, a limitation saying the same is expected. If the report adds limitations the letter never mentioned, such as reliance on a prior study you did not know existed, or an assumed land value, treat those as changes to the engagement and ask the practitioner to explain them in writing. The two documents together are what an examiner, and a later adviser, will use to understand what was agreed and what was delivered; keeping them consistent is part of the practitioner's job and part of yours.
A note on written advice
If a practitioner who practices before the IRS gives you written advice about your return position, Circular 230 sets standards for that advice, including reasonable factual and legal assumptions and consideration of all relevant facts. A study that stays within its lane, classifying and costing, is not that kind of advice, and its limitations should say so. A study that strays into telling you what to claim has taken on obligations its author may not have intended.
What people ask on Reddit and other forums
The searches that lead people to these threads are usually phrased "cost segregation report limitations", "cost segregation report assumptions", "what a cost segregation report contains".
Owners in "cost segregation reddit" threads sometimes post the limitations page of a report and ask whether it is normal. From the sources below:
"The report says it isn't tax advice. Is that a cop-out?" No, it is correct. The practitioner classifies and costs; your adviser decides the return position.
"It says no site visit was made." Acceptable for some properties with complete records; otherwise a warning. The report should say why and what it does to reliability.
"It says costs were estimated. Bad sign?" Normal when records were unavailable, if the estimated items are marked and the method is stated. Hiding estimates inside actual numbers is the bad sign.
"It says for informational purposes only." Then it is not a study you can use for tax reporting. Ask what it is for.
Questions people also ask
Is a long limitations section a bad sign?
Not by itself. Length is not the issue; content is. A long section that discloses estimates, judgement and scope is good practice. A short one that disclaims everything is a warning.
Should the report say the IRS will accept it?
No. No practitioner can promise that, and a report that does is making a claim it cannot support. The IRS publishes what its examiners look for; a good report meets those elements and says so.
What if the report says a site visit was not needed?
Ask why. Complete construction records for a new building can justify it; an older, renovated property usually cannot.
Can I ask for a limitation to be removed?
Yes, by supplying the missing evidence or paying for the additional work. Ask what it would take.
Does my adviser need to read the limitations?
Yes. The adviser is the one relying on the study for a return position and is the person well placed to judge whether a limitation matters for you.
Sources
- https://www.irs.gov/pub/irs-pdf/p5653.pdf — IRS Publication 5653, Cost Segregation Audit Techniques Guide (Rev. 2-2025): Chapters 3, 4 and 5.
- https://www.irs.gov/pub/irs-pdf/pcir230.pdf — Treasury Department Circular No. 230: §10.22, §10.35, §10.37.
- https://www.irs.gov/publications/p527 — IRS Publication 527 (2025), Residential Rental Property: Chapter 3, limits on rental losses.