The CPA's 2026 Cost Segregation Opportunity Guide
Permanent 100% bonus depreciation changed the arithmetic for your real estate clients. This guide is built to be used, not just read: seven triggers, a decision tree, worked illustrations, and two working documents you can put in front of clients this season.
Direct download, PDF, 31 pages. No form, no email required.
What changed for 2026
The rules your clients planned around in 2023 and 2024 are no longer the rules that apply.
100%
Permanent, not phasing down
The One Big Beautiful Bill Act restored the full first-year allowance under §168(k) with no scheduled expiration and no step-down to race.
Jan 19, 2025
The dividing line is acquisition
A 2025 or 2026 placed-in-service date does not automatically get 100%. The written binding contract date controls. A contract signed in November 2024 is still in the 40% world.
Notice 2026-11
Interim guidance, familiar framework
The existing Treas. Reg. §1.168(k)-2 framework applies with updated dates. The binding contract rule, the 10% safe harbor, and the component election carry forward.
Why this matters for cost segregation. Bonus depreciation applies to property with a recovery period of 20 years or less, so a building never qualifies on its own. A study is the mechanism that identifies which portions are properly classified as 5-, 7-, and 15-year property. At a 40% rate that reclassification was worth accelerating. At 100%, the entire reclassified amount is deductible in year one.
Seven triggers worth screening for
If one is true for a client, the conversation is worth having. Two or more, and it usually belongs on the planning agenda in writing.
- 1
The client acquired commercial or rental real estate in the current or prior tax year.
- 2
The client completed a renovation, remodel, tenant improvement, or build-out.
- 3
The client constructed a new building or expanded an existing one.
- 4
The client owns property placed in service in a prior year that never received a study.
- 5
The client has an unusual income year or expects one.
- 6
The client is planning a disposition, demolition, or component replacement.
- 7
The client’s basis changed: 1031 exchange, entity restructuring, step-up at death, or a change in use.
The guide pairs each trigger with why it matters, where to find it in files you already have, and the threshold question that governs all of them: whether the client can actually absorb the deduction under the passive activity, basis, at-risk, and excess business loss rules.
The biggest pool is property clients already own
A property bought in 2019 and depreciated straight-line since then is not a closed file. Changing an impermissible recovery period to a permissible one is a change in method of accounting, made on Form 3115 with a §481(a) catch-up in the year of change. Prior-year returns are not reopened.
| Placed in service | Bonus rate | Notes |
|---|---|---|
| Sept 28, 2017 – Dec 31, 2022 | 100% | TCJA full expensing years |
| 2023 | 80% | First phase-down year |
| 2024 | 60% | |
| 2025, acquired on or before Jan 19, 2025 | 40% | TCJA framework still governs |
| 2025, acquired after Jan 19, 2025 | 100% | OBBBA rate applies |
| 2026 and forward | 100% | Permanent under §168(k) |
On a look-back, the rate is set by the year the property was placed in service, not the year you file the study. That is the single most common misunderstanding in these conversations.
What's inside
Sections 1 through 7 give you the technical grounding. Sections 8 through 10 are the tools you can put in front of clients and across your book of business.
What’s changed for 2026
Permanent 100% bonus depreciation, the January 19, 2025 dividing line, and IRS Notice 2026-11.
The opportunity CPAs may be missing
Why the opportunity is wider than new acquisitions.
The 7 client triggers
A repeatable screen you can run during any planning conversation.
2026 decision tree
Six questions from ownership to opportunity.
Before-and-after illustrations
$1M, $2.5M, and $5M properties, and how reclassification changes deduction timing.
Cost seg + 100% bonus
How the two mechanics interact, and where they do not.
Look-back opportunities
Prior-year property, Form 3115, and the §481(a) catch-up.
The client conversation
Five questions to ask during tax planning.
Opportunity checklist
A one-pager for use across your client base.
Portfolio worksheet
Size the advisory opportunity inside your book of business.
Every technical point is cited to primary authority, including Notice 2026-11, Treas. Reg. §1.168(k)-2, IRS Publication 5653, and Rev. Proc. 2015-13. The illustrations are hypothetical and show deduction timing, not tax savings. The guide is educational material, not tax, legal, or accounting advice.
Put it to work this season.
Thirty-one pages, including a client checklist and a portfolio worksheet your firm may reproduce for internal use.
Direct download, PDF. No form, no email required.
Many states decouple from bonus depreciation. The guide points to our free Multi-State Add-Back Workpaper Kit for the state side.
Run the studies in house.
CostSegPro™ is built into DepreciationPro, with component templates based on the IRS Cost Segregation Audit Techniques Guide. Reclassified assets push straight into the client's asset register, so your firm keeps the fee instead of referring it out.