Research Library Disclaimer
This library is educational. It is not tax, legal, or engineering advice, and it is not a claim about any property’s deductions.
Educational information, not tax advice.
Updated 2026-10-14
Key takeaways
- Nothing here is individualized advice or a study of your building.
- The Audit Techniques Guide is not law.
- Illustrative case studies are hypothetical and do not report savings.
Educational information, not tax advice. CostSeg SI publishes this research library so owners, CPAs, and reviewers can see the statutes, regulations, IRS documents, and court opinions the site uses. Reading a page does not create a client relationship. It does not replace your CPA, tax attorney, or engineer.
Classification of any actual component depends on the facts of that building, the documents, the inspection, and professional judgment. A matrix row, a glossary definition, or an illustrative schedule is not a determination for your property.
The sentences on these pages were written from sources that were opened. They were not written as a return position, an engagement letter, or a study. If a definition on a glossary page and the Code section disagree, the Code section controls. If this disclaimer and any other sentence on the site disagree about whether the library is advice, this disclaimer controls.
Authority and review
Primary authorities are the Code, Treasury regulations, and court opinions. IRS publications, notices, and the Cost Segregation Audit Techniques Guide state administrative or examiner views. Publication 5653 says it is not an official pronouncement of law and cannot be cited as authority.
No qualified tax or legal reviewer has been named for these pages. Draft articles are source-checked where the publication record says verified or partial. They are not expert-reviewed and not client-approved.
The knowledge pages are allowed in search. A named reviewer has not signed them. A word count is not review. Opening a PDF is not a professional opinion about your facts.
What you will not find here
Guaranteed savings, reclassification percentages presented as typical results, testimonials, or credentials that have not been verified. This library has no approved client results to report. Case-study URLs are hypothetical illustrations. They state their assumptions and do not report savings.
A claim that Super Intelligence agents are operational. Workflow screens and “agent” stages on this site are proposed or explanatory unless a later page is approved to say otherwise. Proposed Super Intelligence features did not classify property, did not file Form 3115, and did not review these articles.
A cost-segregation holding under the captions L.A. Darling Co. v. Commissioner, Sperry and Hutchinson Co. v. Commissioner, Clemens v. Commissioner, or Yellow Cab Co. v. Commissioner. Those pages describe the decisions that were opened. They do not supply a building class.
A complete survey of every depreciation opinion, every IRS form, or every state’s conformity statute. California’s nonconformity to §168(k) appears because the 2025 FTB 3885 instructions were opened. Other states are omitted until official pages are opened. Omission is not a statement that those states conform.
How to use the library without treating it as a study
Use the indexes to find the statute, regulation, IRS document, or opinion this site actually opened. Use the glossaries as reading aids. Use the bonus-depreciation reference guide for the October 16, 2026 as-of snapshot of Public Law 119-21 and Notice 2026-11. Then take the primary URL and your building’s facts to a CPA.
Do not copy a matrix row onto a return because a property-type page mentioned it. Do not assume 100 percent bonus depreciation because a component is five-year property; acquisition date, binding contracts, ADS status, and elections still matter. Do not assume a look-back study can ignore a written §1060 allocation; Peco Foods is in this library for that reason.
Do not treat Publication 5653 as current bonus-depreciation law. The February 2025 revision predates the July 4, 2025 statute. Do not treat a glossary definition of placed in service, unit of property, or structural component as if it were Treas. Reg. §1.48-1 or §1.263(a)-3. The regulation text is the rule. The glossary is a teaching sentence.
Limits that stay in place
Educational information, not tax advice. That sentence is the whole point of this page. Nothing in the research methodology, the citation standards, or the update policy converts the library into an engagement. Nothing in a longer article makes a short disclaimer go away.
CostSeg SI can be wrong. Sources can be amended. A PARTIAL case row can be incomplete. A verified paraphrase can still miss a later limitation. The remedy is to open the cited URL and to consult a qualified professional, not to treat a draft educational page as a determination.
If you need a study of a specific building, that work is an engineering and tax engagement with people who inspect, measure, and sign. This library does not perform that work. It explains the sources those people, and this site, are supposed to be able to open.
Time-sensitive sentences — bonus rates, acquisition cutoffs, §179 dollar limits, and automatic-change numbers — are dated to the October 16, 2026 research register. They can go stale. The tax-law update archive lists the statutes and IRS documents that were opened for that register. A later notice or statute is not incorporated until someone opens it and rewrites the as-of sentence. Educational information, not tax advice, remains the rule after that rewrite as well.
Sources
- 1IRS Publication 5653 — Cost Segregation Audit Techniques Guide (rev. 2-2025)(opens in a new tab)
Written for IRS examiners. The guide states it is not an official pronouncement of law and cannot be cited as authority. It predates the July 2025 law.
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