Research · Education
Cost Segregation Knowledge Hub
Browse the CostSeg SI library on cost segregation: fundamentals, tax law, court cases, property guides, and more.
Browse by group
171 articles across seven groups.
Fundamentals
What cost segregation is, how a study is built, and the MACRS classes it uses. Educational, not advice.
25 pagesBrowseTax law & IRS
Code sections, Treasury regulations, and IRS publications this library has opened, with dates and limits noted.
30 pagesBrowseCourt cases
Named decisions and issue indexes that were source-checked. Four captions explain the decision that was found, and say when it is not a cost-segregation case.
29 pagesBrowseProperty guides
How classification usually starts by property type, and which IRS industry matrices exist.
25 pagesBrowseAsset library
Building systems classified by function and permanence under Treas. Reg. §1.48-1, Whiteco, Scott Paper, and IRS matrices—not a guaranteed 5-year list.
24 pagesBrowseCase studies
Hypothetical worked examples. They are not real clients and they do not report savings.
24 pagesBrowseResources
Indexes, glossaries, research method, and the library disclaimer.
14 pagesBrowse
Search the library
Filter by keyword, group, or type of source.
Showing 171 of 171 educational articles.
- FundamentalsCompany educational explanation
What Is Cost Segregation?
Cost segregation separates the cost of a building into components with different tax recovery periods, so parts of the property can be depreciated faster than the building itself. Land stays out of depreciation. The study prices each component and documents the class it belongs in.
Read articleOpen - FundamentalsCompany educational explanation
How a Cost Segregation Study Works
The steps of a typical study, from gathering cost records and inspecting the property to classifying components, reconciling costs, and handing a report to your CPA. Publication 5653 describes six approaches; using actual cost records is the most accurate. The guide is examiner guidance, not a required format.
Read articleOpen - FundamentalsCompany educational explanation
Why Depreciation Matters
Depreciation lets property owners deduct the cost of buildings and equipment over time. The timing of those deductions affects cash flow, which is why recovery periods matter. Land is never depreciable. Section 167 allows the deduction; section 168 computes it.
Read articleOpen - FundamentalsCompany educational explanation
Cost Segregation vs. Standard Depreciation
How depreciation differs when a property is treated as one building versus separated into components, and what changes — and what does not — when you use a study. Total depreciable basis stays the same. Timing, method, and recapture character can change.
Read articleOpen - FundamentalsCompany educational explanation
Personal Property vs. Real Property
The line between tangible personal property (§1245) and real property (§1250) decides most cost segregation outcomes. Treasury Regulation §1.48-1 and the cases that apply it draw that line. Local fixture law does not. Permanence and function are tested together, item by item.
Read articleOpen - FundamentalsCompany educational explanation
Land, Building, and Site Improvements
Every property splits into land, which is not depreciable, the building, and land improvements such as paving and landscaping, which are generally 15-year property. General site grading is usually treated as part of the land. Activity classes can override class 00.3.
Read articleOpen - FundamentalsCompany educational explanation
MACRS Explained
The Modified Accelerated Cost Recovery System sets the depreciation method, recovery period, and convention for most business property. Class lives and a few statutory assignments produce the periods. Salvage value is treated as zero. Buildings use statutory 27.5- or 39-year lives.
Read articleOpen - FundamentalsCompany educational explanation
5-Year Property Explained
Five-year property includes computers, many assets used in retail and service businesses, and personal property in rental housing such as appliances and carpet. The class comes from a class life of more than 4 but less than 10 years, not from a rule that every fixture in a building is 5-year property.
Read articleOpen - FundamentalsCompany educational explanation
7-Year Property Explained
Seven-year property covers office furniture and fixtures, assets in several industry activity classes, and any personal property that has no assigned class life. The class comes from a class life of 10 to under 16 years. It is not a default for building components or structural finishes.
Read articleOpen - FundamentalsCompany educational explanation
15-Year Property Explained
Fifteen-year property is mostly land improvements — paving, sidewalks, fencing, landscaping — plus qualified improvement property and certain retail motor fuels outlets. The class life band is 20 to under 25 years, with a few statutory additions. Buildings and parking garages stay out of class 00.3.
Read articleOpen - FundamentalsCompany educational explanation
27.5-Year Residential Rental Property
Residential rental buildings are depreciated over 27.5 years if at least 80% of their gross rental income comes from dwelling units. Hotels and similar transient lodging do not count. The test is applied building by building, and owner-occupied portions count at rental value.
Read articleOpen - FundamentalsCompany educational explanation
39-Year Nonresidential Real Property
Commercial buildings — offices, stores, warehouses, hotels — are generally depreciated over 39 years, straight-line, using the mid-month convention. Structural components stay with that building class unless the regulations and facts place them elsewhere. The building itself is not bonus-eligible.
Read articleOpen - FundamentalsCompany educational explanation
Depreciable Basis Explained
Depreciable basis is the amount you can depreciate: generally your cost for the property, minus land, adjusted for improvements and prior depreciation. A cost segregation study allocates that number. It does not increase it. Gift, inheritance, and exchange basis rules can change the starting figure.
Read articleOpen - FundamentalsCompany educational explanation
Placed-in-Service Date Explained
Depreciation starts when property is placed in service — ready and available for its intended use — not when you buy it or first collect rent. The date sets the first-year convention, which law applies, and, together with the acquisition date, the bonus percentage. Components of one project can have different dates.
Read articleOpen - FundamentalsCompany educational explanation
Purchase Price Allocation
When you buy a property, the price must be split between land and building, and a study then divides the building portion further. How that split is made affects every later number. A written allocation in an applicable asset acquisition can bind the parties.
Read articleOpen - FundamentalsCompany educational explanation
New Construction Studies
For new buildings, a study can use actual construction cost records — the approach the IRS audit guide calls the most methodical and accurate. Indirect costs are allocated across components. Self-constructed property has its own bonus acquisition-date rules, including a 10% cost safe harbor.
Read articleOpen - FundamentalsCompany educational explanation
Acquisition Studies
When you buy an existing building, construction records are usually unavailable, so a study relies on inspection, drawings, and documented cost estimates reconciled to the purchase price. Land is valued first. Used property can still qualify for bonus depreciation if the acquisition tests are met.
Read articleOpen - FundamentalsCompany educational explanation
Renovation and Improvement Studies
Renovations raise two questions: how to classify the new work, and what to do with the basis of the components that were removed. The tangible property regulations decide what must be capitalized. A study can then classify the capitalized cost and support a partial disposition election.
Read articleOpen - FundamentalsCompany educational explanation
Look-Back Studies
A look-back study applies cost segregation to a property already in service in an earlier year. Missed depreciation is usually claimed through an accounting method change, not by amending old returns. Bonus rates follow the original acquisition and placed-in-service dates, not the year the study is written.
Read articleOpen - FundamentalsCompany educational explanation
Form 3115 and Accounting Method Changes
Form 3115 is how a taxpayer asks to change an accounting method, including how property is depreciated. Many depreciation changes qualify for automatic consent under the current list. The form instructions in force are the December 2022 revision. A current-year study usually does not need the form.
Read articleOpen - FundamentalsCompany educational explanation
Engineering-Based Cost Estimation
When actual costs are not available, studies estimate component costs from drawings, quantities, and published cost data. The IRS audit guide sets out what makes those estimates reliable. Published databases are estimating tools, not tax authority, and a uniform step-up to the purchase price is not an acceptable method.
Read articleOpen - FundamentalsCompany educational explanation
Site Inspections and Documentation
A site inspection records what is actually installed, how it is attached, and what it serves. The IRS audit guide recommends one for every quality study. Photographs, notes, and interviews create the evidence a reviewer will ask for. Drawings show design; the visit shows what was built.
Read articleOpen - FundamentalsCompany educational explanation
Study Reports Explained
What a cost segregation report usually contains, section by section, based on the elements the IRS audit guide lists for a quality report. The asset schedule is what your CPA posts. The narrative and exhibits are what support it. The guide is not a required format and is not legal authority.
Read articleOpen - FundamentalsCompany educational explanation
Working With Your CPA
A cost segregation study classifies and prices components. Your CPA or tax adviser decides how to use it on your return. Bring the CPA in before the study starts so basis, dates, elections, and any prior filings are settled. Educational information, not tax advice.
Read articleOpen - FundamentalsCompany educational explanation
Cost Segregation Terminology Glossary
Plain-language definitions of the terms that appear most often in cost segregation studies and reports. The cited Code sections and regulations control. These summaries are for reading a study, not for taking a return position. Educational information, not tax advice.
Read articleOpen - Tax law & IRSPrimary legal authority
Internal Revenue Code §167 — Depreciation
Section 167 is the base rule that allows a depreciation deduction for property used in a business or held to produce income. It does not set rates or periods. Section 168 supplies the method for most tangible property placed in service after 1986.
Read articleOpen - Tax law & IRSPrimary legal authority
Internal Revenue Code §168 — MACRS
Section 168 sets the Modified Accelerated Cost Recovery System: the methods, recovery periods, conventions, and the alternative system that govern most depreciation of tangible property placed in service after 1986. Cost segregation uses that grid; it does not rewrite it.
Read articleOpen - Tax law & IRSPrimary legal authority
§168(k) — Bonus Depreciation
Bonus depreciation lets a taxpayer deduct a percentage of qualified property’s cost in the year it is placed in service. As of October 16, 2026, the rate is 100 percent for qualified property acquired after January 19, 2025. Earlier binding-contract property stays on the prior phase-down.
Read articleOpen - Tax law & IRSPrimary legal authority
§179 — Expensing Rules and Boundaries
Section 179 lets a business elect to expense qualifying property up to an annual limit. It differs from bonus depreciation in scope, dollar limits, the taxable-income cap, and the property it covers. Limits are stated by tax year. Educational information, not tax advice.
Read articleOpen - Tax law & IRSPrimary legal authority
§1245 Property Overview
Section 1245 property is mainly depreciable personal property and certain other listed property. When it is sold, gain up to prior depreciation is generally taxed as ordinary income. Most short-lived components in a cost segregation study fall here. Educational information, not tax advice.
Read articleOpen - Tax law & IRSPrimary legal authority
§1250 Property Overview
Section 1250 property is depreciable real property that is not §1245 property — generally buildings and their structural components. Its ordinary-income recapture is limited to additional depreciation above straight line. MACRS buildings usually have none of that excess. Educational information, not tax advice.
Read articleOpen - Tax law & IRSPrimary legal authority
§481(a) — Accounting Method Adjustments
When a taxpayer changes an accounting method, §481(a) requires a catch-up adjustment so nothing is counted twice or missed. Look-back cost segregation is usually claimed that way, not by amending every prior return. Filing decisions belong to the taxpayer’s CPA.
Read articleOpen - Tax law & IRSOfficial IRS / government resource
IRS Cost Segregation Audit Techniques Guide
IRS Publication 5653 explains how IRS examiners review cost segregation studies. It is useful guidance, but by its own terms it is not authority, and the February 2025 revision predates the July 2025 law. It is not an IRS-approved study format.
Read articleOpen - Tax law & IRSOfficial IRS / government resource
IRS Tangible Property Regulations
The tangible property regulations decide whether spending on property is deducted or capitalized. For buildings, the improvement test applies separately to the structure and each building system, with elective safe harbors. Older cases are background. Educational information, not tax advice.
Read articleOpen - Tax law & IRSPrimary legal authority
Treasury Regulations for Depreciable Property
A guide to the Treasury regulations cost segregation relies on most: §1.48-1 definitions of personal property and structural components, class-life and placed-in-service rules, general asset accounts, dispositions, and bonus depreciation. Local fixture law is not controlling. Educational information, not tax advice.
Read articleOpen - Tax law & IRSOfficial IRS / government resource
IRS Publication 946
Publication 946, How To Depreciate Property, is the IRS’s plain-language depreciation guide. The 2025 edition reflects the July 2025 law, including 100 percent bonus depreciation after January 19, 2025. No 2026 edition had been released as of October 16, 2026.
Read articleOpen - Tax law & IRSOfficial IRS / government resource
IRS Form 3115 Instructions
A guide to the Form 3115 instructions and the automatic change list taxpayers use to change depreciation methods, including after a look-back cost segregation study. The instructions are dated December 2022. Filing decisions belong to the taxpayer’s CPA. Educational information, not tax advice.
Read articleOpen - Tax law & IRSOfficial IRS / government resource
IRS Form 4562
Form 4562 is where depreciation, §179 expensing, and amortization are reported. The 2025 instructions describe each part and the July 2025 law changes, including 100 percent bonus depreciation for qualified property acquired after January 19, 2025. Educational information, not tax advice.
Read articleOpen - Tax law & IRSCompany educational explanation
MACRS Recovery Periods and Classification
How property is placed in a MACRS class: check the asset classes used in all businesses, then the activity classes, then the statutory defaults. Class lives come from Rev. Proc. 87-56 as reproduced in Publication 946, Appendix B. Educational information, not tax advice.
Read articleOpen - Tax law & IRSCompany educational explanation
Half-Year Convention
The half-year convention treats personal property as placed in service, or disposed of, at the midpoint of the tax year, regardless of the actual month. It is the default convention under §168(d). Buildings use mid-month instead. Educational information, not tax advice.
Read articleOpen - Tax law & IRSCompany educational explanation
Mid-Quarter Convention
The mid-quarter convention applies to a year’s personal property when more than 40 percent of the tested basis is placed in service in the final three months of the tax year. Real property is left out of the test. Educational information, not tax advice.
Read articleOpen - Tax law & IRSCompany educational explanation
Mid-Month Convention
Buildings use the mid-month convention: property is treated as placed in service, or disposed of, at the midpoint of the month. Personal-property components from the same closing generally use half-year or mid-quarter instead. First-year depreciation depends on the month. Educational information, not tax advice.
Read articleOpen - Tax law & IRSCompany educational explanation
Bonus Depreciation Eligibility
Which property qualifies for bonus depreciation under §168(k), including used property, and what is excluded. Eligibility and the applicable rate are separate questions. As of October 16, 2026, 100 percent applies only after January 19, 2025. Educational information, not tax advice.
Read articleOpen - Tax law & IRSCompany educational explanation
Bonus Depreciation Acquisition-Date Rules
Under current law, the bonus depreciation rate depends on when property was acquired. Binding contracts and self-constructed property have specific rules. As of October 16, 2026, 100 percent applies only to qualified property acquired after January 19, 2025. Educational information, not tax advice.
Read articleOpen - Tax law & IRSCompany educational explanation
Placed-in-Service Rules
Property is placed in service when it is first ready and available for its specifically assigned function. That date starts depreciation, sets the convention, and helps determine which bonus rules apply. Actual use is not required. Educational information, not tax advice.
Read articleOpen - Tax law & IRSCompany educational explanation
Qualified Improvement Property
Qualified improvement property is 15-year straight-line property: an interior improvement made by the taxpayer to a nonresidential building after the building was first placed in service. Enlargements, elevators, escalators, and internal structural framework are excluded. Educational information, not tax advice.
Read articleOpen - Tax law & IRSCompany educational explanation
Leasehold Improvement Considerations
When a tenant or landlord pays for interior improvements, who made the improvement affects whether it is qualified improvement property and who depreciates it. Lease terms and tenant-improvement allowances need case-by-case review by the taxpayer’s CPA. Educational information, not tax advice.
Read articleOpen - Tax law & IRSCompany educational explanation
Building Acquisition and Basis Allocation
Basis is generally cost under §1012. Land must be separated because it is not depreciable. In an applicable asset acquisition, a written buyer–seller allocation can bind both parties under §1060 — a risk illustrated by Peco Foods, not a rule for every purchase.
Read articleOpen - Tax law & IRSPrimary legal authority
Related-Party Acquisition Considerations
Buying from a related party can deny bonus depreciation on used property and can deny the §179 election. The tests are statutory purchase rules in §179(d)(2), used by §168(k). A cost segregation study does not override them. Educational information, not tax advice.
Read articleOpen - Tax law & IRSPrimary legal authority
Property Used in a Trade or Business
Depreciation is allowed only for property used in a trade or business or held for the production of income. Personal-use property is outside that rule. Section 179 is narrower than §167 because it requires active conduct of a trade or business.
Read articleOpen - Tax law & IRSPrimary legal authority
Rental Property Depreciation Rules
Residential rental real property is generally recovered over 27.5 years, straight line, using the mid-month convention. Whether a building qualifies depends on an 80 percent dwelling-unit income test in §168(e)(2)(A). Transient lodging is excluded from that definition. Educational information, not tax advice.
Read articleOpen - Tax law & IRSPrimary legal authority
Capital Improvements vs. Repairs
Treasury Regulation §1.263(a)-3 decides whether an amount paid for a building is a deductible repair or a capital improvement. The test is applied to the building structure and to each building system. Older cases, including Plainfield-Union, are background only. Educational information, not tax advice.
Read articleOpen - Tax law & IRSPrimary legal authority
Partial Asset Dispositions
When you replace part of a building, a partial disposition election under Treas. Reg. §1.168(i)-8(d) can let you recognize a loss on the retired portion instead of leaving its remaining basis in the asset. The election is generally made on the original return.
Read articleOpen - Tax law & IRSCompany educational explanation
Federal vs. State Depreciation Differences
States start from the federal Code but may conform to an older date or decouple from bonus depreciation, §179, or §168(n). California is confirmed from FTB 3885. Other states are not listed here until confirmed on official state pages. Educational information, not tax advice.
Read articleOpen - Tax law & IRSOfficial IRS / government resource
Tax Law Updates and Effective Dates
The dates that matter most for current cost segregation work, as of October 16, 2026: 100 percent bonus depreciation after January 19, 2025, 2026 §179 limits, Form 3115 list dates, and the construction and placed-in-service windows for qualified production property.
Read articleOpen - Court casesPrimary legal authority
Hospital Corporation of America v. Commissioner
The Tax Court held that investment-tax-credit tests still decide whether hospital building items are personal property or structural components under ACRS and MACRS. The IRS later agreed with that legal test, not with the item-by-item results.
Read articleOpen - Court casesPrimary legal authority
Whiteco Industries, Inc. v. Commissioner
The Tax Court set out six questions for deciding whether property is an inherently permanent structure or tangible personal property. Those questions are a Tax Court test, not a statute, and they remain the usual permanence analysis in cost segregation.
Read articleOpen - Court casesPrimary legal authority
Commissioner v. Idaho Power Co.
The Supreme Court held that depreciation on equipment a taxpayer uses to build its own capital assets must be capitalized into the cost of those assets. It is a basis case, not a MACRS classification case.
Read articleOpen - Court casesPrimary legal authority
Commissioner v. Lincoln Savings and Loan Association
The Supreme Court held that a required additional premium paid into an FSLIC secondary reserve, in which the institution kept a pro rata interest, was a capital outlay and not a current §162(a) expense.
Read articleOpen - Court casesPrimary legal authority
L.A. Darling Co. v. Commissioner
No federal income-tax opinion was found under the company name L.A. Darling Co. v. Commissioner. The nearest federal depreciation decision with the Darling name is Jay N. Darling v. Commissioner, 4 B.T.A. 499 (1926), which denied automobile depreciation for a nonbusiness use and found a 15-year life for a cartoonist's studio. It does not classify building components.
Read articleOpen - Court casesPrimary legal authority
Massey Motors, Inc. v. United States
A 1960 Supreme Court useful-life and salvage case about automobiles held for short periods and then resold. It is historical background. MACRS later replaced useful-life depreciation for most tangible property.
Read articleOpen - Court casesPrimary legal authority
Sperry and Hutchinson Co. v. Commissioner
No federal depreciation decision was found under Sperry and Hutchinson Co. v. Commissioner. The opened Sperry & Hutchinson tax case is a 1974 Oregon Supreme Court decision on whether interest from the company's investment securities is apportioned to Oregon. It does not classify building components.
Read articleOpen - Court casesPrimary legal authority
Clemens v. Commissioner
Clemens v. Commissioner, T.C. Memo. 1989-205, decides whether a Port Authority police officer could exclude sick-leave pay under section 104(a)(1). The pay came from a labor agreement, not from a workers' compensation statute. The case does not classify building components or depreciable equipment.
Read articleOpen - Court casesPrimary legal authority
Estate of Walling v. Commissioner
The Third Circuit reversed in part a Tax Court holding that barge-repair costs incident to a stock transfer were capital. Repairs made necessary by the partnership’s own prior operation were deductible. The case is historical put-versus-keep law, not a building-classification opinion.
Read articleOpen - Court casesPrimary legal authority
Scott Paper Co. v. Commissioner
The Tax Court allocated a pulp mill’s primary electrical improvements between building use and production-machinery use based on design load. That functional-allocation holding is the leading electrical case in cost segregation, and it is limited to electrical distribution on those mill facts.
Read articleOpen - Court casesPrimary legal authority
Plainfield-Union Water Co. v. Commissioner
The Tax Court allowed a deduction for cleaning and cement-lining a tuberculated water main. The comparison was to the main’s condition before the corrosion, not only to its damaged state. The case is pre-regulation repair law.
Read articleOpen - Court casesPrimary legal authority
Simon v. Commissioner
The Tax Court and the Second Circuit allowed ACRS depreciation on 19th-century Tourte violin bows used by professional musicians, without a separate showing of determinable useful life. The case is about instruments under ACRS, not buildings.
Read articleOpen - Court casesPrimary legal authority
Metro National Corporation v. Commissioner
A Tax Court memorandum opinion classified partitions, lighting, cabinets, ceilings, and sprinkler heads in rental office and medical buildings item by item under the investment tax credit. Similar-looking items went both ways on the facts.
Read articleOpen - Court casesPrimary legal authority
Alamo Broadcasting Co. v. Commissioner
A 1950 Tax Court case allocating a lump-sum radio-equipment purchase, characterizing a diesel-generator loss, and depreciating leasehold improvements over the lease plus renewal. It is historical useful-life law, not a structural-component or intangibles case.
Read articleOpen - Court casesPrimary legal authority
Yellow Cab Co. v. Commissioner
Yellow Cab Co. v. Commissioner, 35 T.C. 791 (1961), denied a Charlotte taxicab company excess-profits-tax relief under section 722 of the 1939 Code. A different case, Yellow Cab Co. of Pittsburgh v. Driscoll, 24 F. Supp. 993 (1938), held that stored cabs stayed depreciable while still devoted to the business. Neither case classifies building components.
Read articleOpen - Court casesPrimary legal authority
Structural Components Decisions
Courts treat walls, floors, ceilings, and systems that serve the building as structural components, generally recovered with the building. HCA applied that definition under MACRS. AmeriSouth shows how often apartment components stay there.
Read articleOpen - Court casesPrimary legal authority
Personal Property Decisions
Cases that treated items as tangible personal property rather than structural components used the regulation, the Whiteco questions, and — on some interiors — a movability record. Winning items in one building are not a checklist for another.
Read articleOpen - Court casesPrimary legal authority
Building Systems Decisions
Courts and the tangible property regulations treat HVAC, plumbing, electrical, elevators, and fire protection as building systems rather than as a pile of removable parts. Dedicated branches can be analyzed separately; the main system often stays with the building.
Read articleOpen - Court casesPrimary legal authority
Electrical Installation Decisions
Scott Paper allowed a load-based split of a mill primary electrical system. Morrison adopted that approach in the Eleventh Circuit. A.C. Monk rejected allocation in the Fourth Circuit. Dedicated equipment circuits are the usual study focus.
Read articleOpen - Court casesPrimary legal authority
Plumbing and HVAC Decisions
Central plumbing and HVAC are listed structural components. Dedicated kitchen, medical, or process hook-ups are where studies and the IRS industry matrices draw a line. Courts have not adopted a Scott Paper-style allocation of those systems as an IRS-accepted method.
Read articleOpen - Court casesPrimary legal authority
Specialized Equipment Decisions
Production machinery, medical equipment, and kitchen equipment are the regulation’s core examples of personal property. Foundations, racks, and hook-ups follow the equipment only when the facts support it. Integration with the building can pull equipment-like items back into §1250.
Read articleOpen - Court casesPrimary legal authority
Land Improvement Decisions
Site work is often 15-year property. Land is not depreciable. Courts have applied the Whiteco questions to signs, vineyard systems, lawn sprinklers, and apartment site features — with results that split on the facts.
Read articleOpen - Court casesPrimary legal authority
Decorative Features Decisions
Ornamental lighting and theme millwork have gone both ways. Shoney’s allowed decorative chandeliers on a restaurant record; the IRS nonacquiesced. AmeriSouth kept apartment millwork, mirrors, and unproved “decorative” fans with the buildings. Function and permanence still control.
Read articleOpen - Court casesPrimary legal authority
Functional Interdependence Decisions
Whether two items work as one asset can affect unit-of-property and placed-in-service questions. Scott Paper’s load split is functional allocation of electrical cost — a different idea. L.L. Bean shows integration with the building. FedEx discussed interdependence in a repairs case about aircraft engines.
Read articleOpen - Court casesPrimary legal authority
Permanent Attachments Decisions
Whiteco’s six questions decide whether an affixed item is an inherently permanent structure. They are a Tax Court test, not a statute. How something is bolted down is evidence, not the whole inquiry. L.L. Bean and King Radio mark opposite ends of the same scale.
Read articleOpen - Court casesPrimary legal authority
Cost Estimation Evidence Decisions
When original invoices are missing, studies estimate costs. Both classification and numbers have to be proved. Boddie-Noell rejected after-the-fact percentages. AmeriSouth rejected most of an aggressive takeoff. Peco held that a later study cannot override a binding written §1060 allocation.
Read articleOpen - Court casesPrimary legal authority
Depreciation Basis Decisions
Idaho Power requires capitalizing self-construction costs into basis. Peco Foods bound a buyer to a written purchase-price allocation. Massey and Alamo are historical useful-life law. Simon is ACRS history about instruments, not buildings.
Read articleOpen - Court casesPrimary legal authority
Repairs and Capitalization Decisions
Building work today is tested under Treas. Reg. §1.263(a)-3. Lincoln Savings and INDOPCO are the Supreme Court capitalization cases. Plainfield-Union, Walling, and FedEx are older repair opinions that supply vocabulary, not the current building rule.
Read articleOpen - Court casesCompany educational explanation
Reviewed Case Index
An index of the court decisions CostSeg SI has source-checked for this library, with weight and limits noted. It is not a complete survey of all depreciation cases, and it is not titled “recent” because the core opinions are decades old.
Read articleOpen - Property guidesCompany educational explanation
Single-Family Rental Properties
A house held out for rent is usually 27.5-year residential rental property when the §168(e)(2) dwelling-unit test is met. The IRS residential rental matrix then separates appliances, some floor coverings, and site work from the dwelling itself. This page is educational information, not tax advice.
Read articleOpen - Property guidesCompany educational explanation
Multifamily Apartment Buildings
Garden and mid-rise apartments that meet the 80% dwelling-unit test are 27.5-year residential rental property. A stand-alone clubhouse or leasing office on the same site is 39-year property in the IRS residential matrix. AmeriSouth is the caution case for aggressive apartment component lists.
Read articleOpen - Property guidesCompany educational explanation
Condominiums and Townhomes
A rented condominium unit is analyzed as residential rental property only if the owner’s activity meets the §168(e)(2) dwelling-unit test. The IRS residential matrix names condos, but association-owned common elements are a separate ownership question. This page is educational information, not tax advice.
Read articleOpen - Property guidesCompany educational explanation
Build-to-Rent Communities
Purpose-built rental houses and duplexes are classified by use and ownership, not by the build-to-rent label. Dwelling buildings that meet the 80% test are generally 27.5-year property; shared amenities and streets are separate buildings or site work. There is no IRS build-to-rent matrix.
Read articleOpen - Property guidesCompany educational explanation
Student Housing
Purpose-built student housing may be residential rental property or transient lodging, depending on how the units are used. Section 168(e)(2) and Publication 527 supply the test; no IRS student-housing matrix was found. Confirm the building class with a CPA before classifying furniture.
Read articleOpen - Property guidesCompany educational explanation
Senior Living Facilities
Independent-living campuses mix dwelling units with dining, clinic, and office buildings. Residential versus nonresidential classification follows the §168(e)(2) 80% dwelling-unit test, which this page describes but does not decide. No IRS senior-living matrix was found.
Read articleOpen - Property guidesCompany educational explanation
Assisted Living Facilities
Assisted living sits between housing and healthcare. Whether a building is 27.5-year residential rental property depends on the §168(e)(2) dwelling-unit test, which this page describes and does not decide. No IRS assisted-living matrix was found.
Read articleOpen - Property guidesCompany educational explanation
Hotels and Resorts
Hotels are generally 39-year nonresidential real property because transient lodging is excluded from the dwelling-unit definition. Guest-room furniture is 5-year property in the IRS casino and hotel matrix. That matrix is examiner guidance written for hotel/casino complexes, not a statute for every resort.
Read articleOpen - Property guidesCompany educational explanation
Motels and Extended-Stay Properties
Motels follow hotel treatment when occupancy is transient: the building is generally 39-year property. Extended-stay products add kitchens and longer stays, which can change facts for the dwelling-unit test but are not a published IRS category. Confirm the test with a CPA.
Read articleOpen - Property guidesCompany educational explanation
Restaurants and Fast-Food Properties
Restaurant buildings are generally 39-year nonresidential real property. The IRS restaurant matrix is one of the most detailed industry tables: kitchen equipment and dedicated hook-ups are 5-year there; central HVAC is building. Rev. Proc. 2002-12 is a smallwares expensing method, not a 15-year building rule.
Read articleOpen - Property guidesCompany educational explanation
Office Buildings
Office buildings are generally 39-year nonresidential real property. There is no IRS office matrix. Metro National classified some partitions and lighting as personal property on one owner’s facts. Later interiors may be qualified improvement property if §168(e)(6) is met.
Read articleOpen - Property guidesCompany educational explanation
Medical and Healthcare Facilities
Hospitals, imaging centers, and medical office buildings are generally 39-year nonresidential real property. HCA is the leading hospital classification case. There is no IRS medical-office matrix. Equipment is typically personal property; the rooms around it often are not.
Read articleOpen - Property guidesCompany educational explanation
Retail Stores
Retail buildings are generally 39-year nonresidential real property. The IRS retail matrix covers department and grocery stores: fixtures and strippable floor covering are 5-year there; ceramic tile and parking structures are building. The matrix is examiner guidance from a 2004 field directive.
Read articleOpen - Property guidesCompany educational explanation
Shopping Centers
A shopping center is a group of 39-year buildings plus 15-year site work. The retail matrix is the closest IRS table, written for department and grocery stores. Who owns the interior work decides whose basis it is, and a written purchase allocation can bind the parties under Peco Foods.
Read articleOpen - Property guidesCompany educational explanation
Warehouses
Warehouse shells are generally 39-year nonresidential real property. There is no IRS warehouse matrix. Rack systems and material-handling equipment are usually personal property; dock structure is usually building. A warehouse used only for storage is not qualified production property.
Read articleOpen - Property guidesCompany educational explanation
Distribution Centers
Fulfillment and distribution buildings mix a 39-year shell with extensive material-handling systems. Classification follows function, not the word automation. There is no IRS distribution-center matrix. Conveyors and AS/RS equipment are typically personal property; the shell is not.
Read articleOpen - Property guidesCompany educational explanation
Self-Storage Facilities
Self-storage buildings are generally 39-year nonresidential real property. Unit partitions, site paving, and office fit-out are the usual study lines. No IRS self-storage matrix was found. This page does not decide whether unit walls are structural components.
Read articleOpen - Property guidesCompany educational explanation
Manufacturing Facilities
Process equipment is personal property. The factory building is 39-year property unless an elective qualified-production-property allowance applies to a qualifying portion. Section 168(n) is temporary, elective, and excludes office, parking, sales, and research space. This page draws no eligibility conclusion.
Read articleOpen - Property guidesCompany educational explanation
Automotive Dealerships
Dealership buildings are generally 39-year property. The IRS auto-dealership matrix is specific: showroom display lighting and merchandise-lot lighting can be 5-year; floor-pit structure is building. Bollards are classified by what they protect.
Read articleOpen - Property guidesCompany educational explanation
Auto Repair Facilities
Standalone repair shops share pit, lift, and exhaust issues with dealership service bays. There is no separate IRS repair-shop matrix. Lifts are tangible personal property under the regulation; the pit structure is building in the dealership matrix. Quick-lube canopies are not automatically 5-year property.
Read articleOpen - Property guidesCompany educational explanation
Gas Stations and Convenience Stores
A qualified retail motor-fuels outlet can be 15-year section 1250 property under §168(e)(3)(E)(iii). Rev. Rul. 2003-54 treats typical stand-alone pump canopies as 5-year property and their footings as 15-year land improvements. Rev. Proc. 97-10 is a historical election for older stations, not a restaurant rule.
Read articleOpen - Property guidesCompany educational explanation
Data Centers
Data halls mix a 39-year shell with large amounts of process electrical, cooling, and raised-floor equipment. There is no IRS data-center matrix. Sole-justification cooling and dedicated process power need engineering support. Life-safety generators are building in other matrices; process generators are closer to equipment.
Read articleOpen - Property guidesCompany educational explanation
Mixed-Use Buildings
A building with apartments over retail can be residential rental, nonresidential, or more than one building for tax purposes. The 80% dwelling-unit test in §168(e)(2) is the starting point. Getting 27.5 versus 39 wrong dominates any later component study.
Read articleOpen - Property guidesCompany educational explanation
Parking Structures and Garages
Stand-alone parking garages are buildings under Treas. Reg. §1.48-1(e)(1) and the IRS retail matrix, recovered over 39 years. Surface lots are 15-year land improvements. ATG Chapter 8.B rejects 15-year treatment of open-air parking structures and mentions penalties.
Read articleOpen - Property guidesCompany educational explanation
Specialty and Recreational Properties
Gyms, theaters, bowling centers, and similar buildings are usually 39-year property unless a specific activity class applies. Publication 946 class 79.0 is 7-year recreation property and excludes golf courses, stadia, and the buildings that house the assets. The casino matrix is the only recreation-heavy ATG table.
Read articleOpen - Asset libraryCompany educational explanation
Specialized Electrical Systems
Process power, emergency generation, and equipment-only electrical capacity are classified by function under Treas. Reg. §1.48-1, court tests, and IRS examiner matrices. Building life-safety power usually stays with the building. Mixed primary systems have been allocated by design load in some cases and rejected in others. This page is educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
General Electrical Distribution
Service, house panels, and convenience circuits that light and power the building are listed structural components under Treas. Reg. §1.48-1(e)(2). A mixed primary system has been split by design load in some cases. Publication 5653 limits that functional allocation to primary and secondary electrical distribution. This page is educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Dedicated Equipment Wiring
Branch circuits that exist only to serve a named appliance or machine are the usual equipment-side electrical items in IRS industry matrices. General-use outlets stay with the building. Functional allocation of a mixed primary system is a separate, narrower method that Publication 5653 limits to primary and secondary electrical distribution. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Decorative and Specialty Lighting
Display, theme, and decorative lighting has been treated as personal property in some cases and IRS industry matrices, and as a structural component when it is the room’s primary illumination. Treas. Reg. §1.48-1 lists lighting fixtures among structural components. Whiteco permanence factors are a court test, not a statute. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
General Building Lighting
Fixtures that illuminate corridors, stairs, restrooms, and work areas so the building can be occupied are listed structural components under Treas. Reg. §1.48-1(e)(2). Changing lamp type does not, by itself, change the class. Decorative exceptions are fact-specific and are discussed on the specialty-lighting page. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Plumbing Fixtures and Specialty Plumbing
Restroom plumbing and building domestic water and drain systems are listed structural components. Dedicated equipment hook-ups and process piping are the specialty cases in IRS matrices and in some court records. Functional allocation as described for electrical systems is not an IRS-accepted plumbing method. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
HVAC and Climate-Control Systems
Central heating and air conditioning that condition a building are listed structural components. Separate machinery whose sole justification is process temperature or humidity can be personal property. Publication 5653 restaurant matrices say allocating a mixed HVAC unit is not appropriate. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Specialized Ventilation Systems
Equipment exhaust, makeup air solely for that exhaust, and process filtration are treated as following the equipment in several IRS industry matrices. Building restroom and occupancy exhaust stays with the building. The HVAC sole-justification test is a regulation exception, not an electrical load split. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Flooring and Floor Coverings
Structural slabs, ceramic tile, wood, and epoxy are treated as building in IRS examiner matrices. Strippable vinyl and carpet are treated as not permanent in several industry tables. Permanence is a Whiteco court test, not a statute, and matrices differ by industry. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Carpeting and Specialty Flooring
Carpet is treated as not permanent in the restaurant, retail, and residential IRS matrices. Permanently adhered carpet is building in the pharmaceutical table. Raised access floors and athletic surfaces are not carpet rows. Whiteco permanence factors are a court test, not a statute. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Cabinetry and Built-In Casework
The same cabinet box can be building or personal property depending on function. Residential kitchen cabinets are building in the IRS residential matrix. Dealership sales cabinets are personal property in that matrix; restroom cabinets are building. Metro National allowed cabinets on office facts. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Specialized Millwork
Theme and decorative millwork is treated as personal property in the restaurant matrix. Finish carpentry that completes an apartment often stayed with the building in AmeriSouth. Ornament is not a recovery class by itself. Whiteco permanence factors are a court test, not a statute. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Appliances and Equipment
Kitchen appliances in residential rentals are treated as class 57.0 personal property in the IRS residential matrix. Treas. Reg. §1.48-1(c) names refrigerators and production machinery as tangible personal property. Built-in stove hoods are building in that same matrix. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Restaurant Kitchen Equipment
Cooking lines, refrigeration, and dedicated hook-ups are treated as class 57.0 personal property in the IRS restaurant matrix. Smallwares may be materials and supplies under Rev. Proc. 2002-12, which is not a building-life rule. Central HVAC remains building, and allocation of a mixed unit is not appropriate. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Medical and Specialty Equipment
Imaging, laboratory, and treatment equipment is machinery under Treas. Reg. §1.48-1(c). The room, shielding, and building HVAC around it often are not. Hospital Corp. of America applied investment-credit tests under MACRS; the IRS did not acquiesce in the item results. There is no IRS medical-office matrix. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Security and Access-Control Systems
Building-protection security is a listed building system for improvement testing and is treated as building property in the retail IRS matrix. Anti-shrink surveillance is personal property in that matrix. Apartment surveillance equipment was among the items allowed in AmeriSouth. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Fire Protection and Safety Systems
Sprinkler systems, fire escapes, and related life-safety components are listed structural components in Treas. Reg. §1.48-1(e)(2). Equipment-specific suppression can be personal property in some IRS matrices. Courts have split on sprinkler-type items depending on facts. Do not declare fire sprinklers personal property as a rule. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Telecommunications and Data Wiring
Low-voltage cabling that serves equipment is treated as class 57.0 personal property in the IRS residential matrix. Building communication risers can still be structural. AmeriSouth allowed cable, phone, and data outlets on its facts. Whiteco permanence factors are a court test, not a statute. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Interior Partitions and Decorative Features
Treas. Reg. §1.48-1 lists partitions among structural components. King Radio treated a movable, non-load-bearing system as personal property. Metro National allowed some partitions and denied atrium storefront walls. Restaurant theme elements are personal property in that matrix; apartment millwork often stayed with the building in AmeriSouth. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Landscaping and Irrigation
Land is not depreciable. Landscaping that would be destroyed with a related depreciable asset is often class 00.3 land-improvement property as reproduced in Publication 946 Appendix B. The dealership matrix uses that replacement test. Trentadue classified vineyard irrigation as a land improvement and trellises as personal property. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Parking Lots, Sidewalks and Paving
Surface parking, sidewalks, curbs, and landscape islands are land improvements in IRS examiner matrices and in class 00.3 as reproduced in Publication 946. Paved parking areas are not tangible personal property under Treas. Reg. §1.48-1(c). Parking structures are buildings. Land is not depreciable. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Fencing, Gates and Site Features
Fences are not tangible personal property under Treas. Reg. §1.48-1(c). They are often class 00.3 land improvements in Publication 946. Dealership bollards are classified by what they protect. Sign structures and faces can split classes, as Whiteco and Rev. Rul. 2003-54 illustrate. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Roofing and Structural Components
Roofs, walls, floors, foundations, windows, and doors are listed structural components under Treas. Reg. §1.48-1(e)(2) and are generally section 1250 building property. Decorative roof elements can still be part of the roof. Qualified improvement property does not include roofs. Educational information, not tax advice.
Read articleOpen - Asset libraryCompany educational explanation
Asset Classification Evidence and Documentation
Publication 5653 lists 13 principal elements of a quality cost segregation study and nine report elements. Classification must be substantiated with records, a site inspection, and a written legal analysis. Rule-of-thumb percentages without documents are the weakest approach in that guide. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Single-Family Rental Acquisition
A worked example of allocating a house purchase among land, 27.5-year building, 5-year appliances, and 15-year driveway. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Multifamily Acquisition
A hypothetical apartment purchase used to show clubhouse (39-year), dwellings (27.5-year), site work (15-year), and appliances (5-year) on one ticket. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Hotel Property
A hypothetical limited-service hotel used to separate 39-year building, 5-year guest-room furniture, and 15-year surface parking. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Restaurant Property
A hypothetical restaurant build-out highlighting dedicated kitchen utilities versus central HVAC, using the IRS restaurant matrix. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Office Building
A hypothetical office purchase used to show 39-year structure, possible movable partitions, and later QIP interiors. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Warehouse
A hypothetical dry warehouse with racking and a truck court, showing how little of a simple box is short-life property. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Retail Property
A hypothetical grocery using the IRS retail matrix for fixtures, strippable flooring, and a parking field. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Medical Facility
A hypothetical imaging clinic used to separate machines and dedicated power from the 39-year medical office building. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Self-Storage Property
A hypothetical climate-controlled storage facility used to keep hallway lighting with the 39-year building and isolate gates, fencing, and office furniture. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Manufacturing Facility
A hypothetical plant used to show process electrical versus building electrical, and to flag — without claiming — the §168(n) window. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative New Construction Project
How a study uses AIA pay applications to map dollars to components when the building is being finished. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Renovation Project
A hypothetical interior renovation used to show capitalization, possible QIP, and a partial disposition of a retired roof or HVAC unit. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Property With Limited Records
What a study can still do when invoices are gone: inspection, drawings, and cited unit-cost estimates reconciled to basis. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Bundled Contractor Costs
How a study unbundles a single “electrical” pay-application line into building lighting and dedicated equipment circuits. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Blueprint Analysis
Using drawings to locate dedicated utilities and quantities before the site visit, then confirming them in the field. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Site Improvements
A hypothetical pad site used to split land, 15-year lot and fence, 5-year sign face, and 39-year building. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Specialized Equipment
A hypothetical bottling line used to keep process utilities with the equipment class and building utilities with the building. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Look-Back Study
How a study on a building placed in service years ago feeds a Form 3115 and a §481(a) adjustment rather than amended returns. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Bonus Depreciation Comparison
Why two properties with the same components can have different first-year bonus: acquisition date, binding contracts, and used-property rules. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative MACRS Recovery-Period Comparison
A side-by-side of 5-, 7-, 15-, 27.5-, and 39-year treatment for typical buckets, without claiming any property mixes them in those shares. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Cost Estimation and Reconciliation
The arithmetic a quality study must show: component costs add to depreciable basis, and estimates are scaled if the first pass misses the total — with the audit guide’s limits on step-up factors. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Asset Classification Review
A human review pass that challenges 5-year labels against Treas. Reg. §1.48-1 and the relevant IRS matrix. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
Illustrative Quality Assurance Review
Checks a draft study for missing photos, broken reconciliations, and classes that lack a cited authority — using the ATG’s quality elements as what examiners look for. Educational information, not tax advice.
Read articleOpen - Case studiesSample study
How to Interpret a Final Asset Schedule
How a CPA or owner should read recovery class, placed-in-service date, convention, cost, and remaining basis columns without treating the schedule as a filed return. Educational information, not tax advice.
Read articleOpen - ResourcesCompany educational explanation
Court Case Index
A map of the named decisions and topic pages in this library, including four inventory URLs that stay unpublished.
Read articleOpen - ResourcesCompany educational explanation
Tax Code and Regulation Index
The Internal Revenue Code sections and Treasury regulations this library actually cites, with a pointer to the page that discusses each one.
Read articleOpen - ResourcesCompany educational explanation
IRS Publications and Forms Index
IRS publications, notices, revenue procedures, and form instructions this library cites, with the date of the version that was opened.
Read articleOpen - ResourcesCompany educational explanation
Property-Type Guide Index
How to use the property guides, and which seven IRS industry matrices exist versus which property types have none.
Read articleOpen - ResourcesCompany educational explanation
Asset Classification Index
A map of the asset-library pages, grouped by building system, with the tests that actually decide class.
Read articleOpen - ResourcesCompany educational explanation
Cost Segregation Glossary
Short definitions of the study vocabulary used on CostSeg SI pages. The cited authorities control if a definition and a statute disagree.
Read articleOpen - ResourcesCompany educational explanation
MACRS and Depreciation Glossary
Definitions of recovery periods, conventions, bonus depreciation, §179, and related Code terms used throughout this library.
Read articleOpen - ResourcesCompany educational explanation
Engineering and Construction Glossary
Construction and estimating terms that appear in studies. They describe how costs are measured. They are not tax classes.
Read articleOpen - ResourcesCompany educational explanation
Bonus Depreciation Reference Guide
Current-law bonus depreciation rates, acquisition-date rules, and eligibility limits as verified as of October 16, 2026.
Read articleOpen - ResourcesCompany educational explanation
Research Methodology
How CostSeg SI chooses, grades, and limits sources before a page is written. Research can be source-checked. It is not a substitute for named expert review.
Read articleOpen - ResourcesCompany educational explanation
Source and Citation Standards
What a CostSeg SI citation must include, which URLs are allowed, and when a page is marked verified, partial, or held.
Read articleOpen - ResourcesCompany educational explanation
Content Review and Update Policy
How a page moves from drafted to publishable, why expert review is required, and what “update” means after a statute or IRS notice changes.
Read articleOpen - ResourcesCompany educational explanation
Tax Law Update Archive
Dated notes of the statutes and IRS documents that changed depreciation practice for this library’s 2026 research, not a news feed.
Read articleOpen - ResourcesCompany educational explanation
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.
Read articleOpen
Need help choosing a starting point?
Begin with Fundamentals, or request a study conversation if you already have a property in mind.