How to Calculate UBIA of Qualified Property: Cost, Period, Records

To calculate the unadjusted basis immediately after acquisition (UBIA) of qualified property, take the original cost of each depreciable business asset on the date it was first placed in service, add every cost capitalized into that asset at acquisition, and ignore all depreciation, bonus depreciation, and Section 179 expensing you have claimed since. Keep the asset in the total only while it remains within its depreciable period, and only if you still own it at year-end and used it in the business during the year. Sum the qualifying assets across the business, and that figure is your UBIA.

Start With Original Cost, Not Book Value

UBIA equals the cost basis of the property on the date it was first placed in service, with no reduction for depreciation, bonus depreciation, or Section 179 expensing taken in any year.¹ This is the point that trips people up most often. An asset you fully wrote off under Section 179 still carries its original purchase price as UBIA. You already took the write-off; the property-based figure keeps working for you separately.

The basis includes every cost capitalized into the asset at acquisition: the purchase price, sales tax, delivery charges, installation labor, and any testing or setup costs needed to make the property operational. Buy a commercial oven for $40,000, pay $3,500 in freight and $1,500 for electrical hookup, and the UBIA is $45,000. Not $40,000.

Tax credits that reduced your book basis do not reduce UBIA either. If you claimed an investment tax credit under Section 50(c) that lowered the asset’s adjusted basis on your books, your UBIA still sits at the original cost.¹

Capital improvements are handled as separate items of property. A $20,000 roof replacement on a rental building is its own UBIA item with its own placed-in-service date, distinct from the building. Track each improvement separately, because its depreciable-period clock runs on its own dates.

Which Assets Qualify

Not every business asset counts. The statute limits UBIA to tangible property that meets all four of these conditions:²

The property is subject to depreciation under the tax code — buildings, machinery, equipment, vehicles, furniture.
You still own it on the last day of your tax year. Sell equipment on December 30 and its basis drops out for that year.
It was actively used in the business at some point during the year, not sitting in storage awaiting future deployment.
Its depreciable period has not yet ended by the close of the tax year.

Land never qualifies, because it is not depreciable. Intangible assets like patents, trademarks, and goodwill also fail the test, because they are amortized rather than depreciated under Section 168. For property you use partly for business and partly for personal purposes, only the business-use percentage of the basis counts.¹

The Depreciable Period Decides When Assets Drop Out

An asset contributes to your UBIA total only while it stays inside its depreciable period. That period runs from the placed-in-service date until the later of:³

Ten years after the placed-in-service date, or
The last day of the last full year of the asset’s recovery period under Section 168.

For most personal property — equipment, vehicles, computers — the recovery period runs 5 or 7 years, so the 10-year floor controls. A $60,000 piece of 5-year equipment placed in service in 2020 stays in your UBIA through 2030, even though its tax depreciation ended years earlier. In 2031 it drops out, whether or not you still use it every day.

Real property runs the other direction. Nonresidential buildings carry a 39-year recovery period, and residential rental property runs 27.5 years. Both exceed 10 years, so the recovery period controls. A warehouse placed in service in 2005 with a 39-year recovery period sits in your UBIA total through the end of 2044. Getting sloppy with these dates means dropping a building too early or keeping equipment that aged out three years ago.

Like-Kind Exchanges, Inherited Property, and Gifts

When property comes to you through something other than a straight cash purchase, the starting number changes.

Section 1031 Exchanges

Swap business property in a like-kind exchange and the replacement property’s UBIA starts with the UBIA of the property you gave up, not the new property’s fair market value and not your adjusted basis at the time of the exchange. Cash you added (boot paid) increases the UBIA; excess boot you received decreases it.¹

When the replacement UBIA exceeds the relinquished UBIA because you added cash, the replacement property splits into two items for depreciable-period purposes. The portion equal to the old UBIA keeps the original placed-in-service date. The excess — the boot you paid — gets a new placed-in-service date as of the exchange. Each portion runs its own clock.

Exchange a building with $500,000 UBIA for a new building and add $100,000 in cash, and the replacement carries $600,000 total UBIA. The first $500,000 traces back to when you originally placed the old building in service. The other $100,000 starts fresh on the exchange date.¹

Inherited Property

Property inherited from a decedent generally receives a stepped-up basis equal to fair market value at the date of death.⁴ That stepped-up value becomes your UBIA, and a brand-new depreciable period starts on the date of death. A building the decedent bought 35 years ago for $200,000 that was worth $900,000 at death gives you $900,000 in UBIA with a full new depreciable period running from that date.

Gifted Property

Gifts follow the opposite rule. When you receive business property as a gift while the donor is alive, your basis for depreciation purposes is generally the donor’s adjusted basis.⁴ For UBIA, the transferee’s figure equals the transferor’s UBIA and the original placed-in-service date carries over. You step into the donor’s shoes for both the amount and the clock, so a gift of property near the end of its depreciable life delivers limited QBI benefit.

If You Own Through a Partnership or S Corporation

Partnerships and S corporations calculate total UBIA at the entity level, then allocate a share to each owner and report it on Schedule K-1. Partnerships put the Section 199A information at Box 20, Code Z.⁵ S corporations use Box 17, Code V.⁶ You carry the number from the K-1 to Form 8995-A.

Allocation methods differ. Partnerships allocate UBIA the same way they allocate depreciation on the underlying asset. If the partnership agreement gives you 60% of a machine’s depreciation, you get 60% of its UBIA. S corporations allocate pro rata using per-share, per-day ownership, the same method used for most S corporation items. Own shares for half the year, get roughly half the UBIA.⁶

Related-Party Transfers Do Not Reset the Clock

The statute authorizes the Treasury to shut down attempts to game the depreciable period through related-party transactions.² Without those rules, you could sell fully depreciated equipment to a related entity, restart the placed-in-service date, and keep collecting UBIA on property that should have aged out.

The regulations apply principles similar to Section 179(d)(2), which disallows expensing for property acquired from related parties. Selling an asset to a family member’s LLC or between commonly controlled entities does not reset the depreciable-period clock. The replacement inherits the original placed-in-service date, not the transfer date. If you have run 1031 exchanges between related entities, check that your UBIA calculations reflect the original service dates.

Why UBIA Matters and When It Applies

UBIA only affects your QBI deduction if your taxable income clears the threshold where the wage-and-property cap kicks in. For 2026, the One Big Beautiful Bill Act made the QBI deduction permanent and set those thresholds at $201,750 for single filers and $403,500 for joint filers. Below them, you take 20% of qualified business income and UBIA never enters the picture.

Above the threshold, the deduction for each business cannot exceed the greater of 50% of W-2 wages paid by the business, or 25% of W-2 wages plus 2.5% of UBIA.⁷ The property-based option exists for capital-intensive businesses like real estate and manufacturing that own significant depreciable assets but pay limited wages. Without UBIA in the formula, a landlord who contracts out management and pays minimal wages would hit a wall.⁸

Records to Keep

UBIA lives or dies on documentation. Because you need the original cost on the placed-in-service date rather than the depreciated book value on your current balance sheet, you may need records going back decades for long-lived property like buildings. For every asset in your calculation, keep:

Purchase records — closing statements, bills of sale, or purchase contracts showing the full acquisition cost including sales tax, freight, and installation.
Improvement records — invoices and contractor receipts for each capital improvement, with the specific placed-in-service date. Each improvement is its own UBIA item.
Exchange documentation — closing statements for both the relinquished and replacement properties in a 1031 exchange, showing any boot paid or received.
Depreciation schedules — prior-year Forms 4562 and internal ledgers tracking original basis, placed-in-service date, and recovery period for each asset.⁹
Gift or inheritance records — for inherited property, the estate’s Form 706 or Statement of Estate Tax Value (Form 8971/Schedule A) showing date-of-death value; for gifted property, records of the donor’s original basis and placed-in-service date.

Cross-reference accounting ledgers with bank statements to confirm that ancillary costs — testing, permits, hookup fees — got capitalized into the asset rather than expensed. Those overlooked costs are free UBIA. They increase your property-based limitation without requiring any additional investment.

1
Code of Federal Regulations. 26 CFR 1.199A-2
2
Office of the Law Revision Counsel. 26 U.S. Code 199A – Qualified Business Income
3
eCFR. 26 CFR 1.199A-2 – Determination of W-2 Wages and Unadjusted Basis Immediately After Acquisition of Qualified Property
4
Internal Revenue Service. Basis of Assets
5
Internal Revenue Service. Partners Instructions for Schedule K-1 (Form 1065) (2025)
6
Internal Revenue Service. Shareholders Instructions for Schedule K-1 (Form 1120-S) (2025)
7
eCFR. 26 CFR 1.199A-1 – Operational Rules
8
Internal Revenue Service. Qualified Business Income Deduction
9
Internal Revenue Service. 2025 Instructions for Form 4562