Iowa Bonus Depreciation: Full Conformity Since 2023, By Placed-in-Service Date.
Iowa's bonus-depreciation add-back was repealed retroactively to property placed in service on or after January 1, 2023. The date that controls is when the PROPERTY was placed in service — not the tax year you happen to be filing.
Reviewed by Cost Seg Smart Editorial Team · Last verified against Iowa Code §422.3(5) — IRC conformity, Iowa Code §422.7 — individual modifications incl. repeal note
The 30-second answer: Iowa conforms to federal §168(k) bonus depreciation — no add-back — for property placed in service on or after 2023-01-01. The bonus-depreciation add-back subsections were repealed retroactively to that date, and Iowa has had rolling IRC conformity since tax years beginning 2020-01-01.
The date that matters is easy to get wrong: it is the property's placed-in-service date, not the tax year of the return. Property placed in service before 2023-01-01 was subject to Iowa's add-back and, further back, a static (not rolling) IRC conformity date through 2019 — a lookback study or Form 3115 catch-up on older property needs separate review.
On a representative Iowa single-family rental placed in service in 2023 or later (the single-family rental band we publish, 9–32% of depreciable basis reclassified, 16% representative), the reclassified components alone generate an estimated $18K–$165K of federal Year-1 depreciation — roughly $6,660–$61,570 of federal Year-1 tax savings at the 37% top bracket, with the same amount flowing through to Iowa with no add-back.
The date that controls: placed-in-service, not tax year
It is tempting to read "Iowa conforms since 2023" as "Iowa conforms starting with the 2023 tax year" and stop there. That reading misses the actual mechanism: Iowa's bonus-depreciation add-back subsections were repealed retroactively to property placed in service on or after 2023-01-01. The controlling fact is when the property itself was placed in service — a specific, fixed date attached to the asset — not the tax year of whichever return is currently being prepared.
In practice this rarely causes confusion for a routine new purchase: a property bought and placed in service today was obviously placed in service after 2023-01-01, so the modern full-conformity answer applies cleanly. The distinction becomes load-bearing in two situations: a lookback cost segregation study on a property that has been held for years, and a Form 3115 §481(a) catch-up, where the tax year of the catch-up can be well after 2023 even though the underlying property was placed in service earlier — sometimes before 2023-01-01.
For property placed in service before 2023-01-01, Iowa required a bonus-depreciation add-back. And further back than that, Iowa was on a static Internal Revenue Code conformity date — 2018-03-24 — through 2019, rather than the rolling conformity Iowa has used since 2020. That earlier period could mean a different definition of qualified property and a different bonus percentage than current federal law provides. None of this is theoretical for a study that reaches back several years: the placed-in-service date of the specific property, not the year the study or the catch-up is filed, decides which Iowa rule set applies.
The practical rule: before telling a client "Iowa conforms, no add-back," confirm the placed-in-service date of the property in question. If it is 2023-01-01 or later, the modern answer holds. If it is earlier, treat the Iowa-level answer as a separate question requiring its own review.
Federal vs Iowa, Side by Side
For an individual or corporate taxpayer's cost-segregation-reclassified components, split by placed-in-service date:
| Placed-in-service date | Federal (IRC) | Iowa |
|---|---|---|
| 2023-01-01 or later | 100% may apply to qualified property acquired and placed in service after January 19, 2025, subject to §168(k) eligibility, related-party/prior-use, binding-contract, and election rules | Full conformity, no add-back. Add-back subsections repealed retroactively to this date (Iowa Code §422.7, §422.35) |
| Before 2023-01-01 (but after 2019 rolling-conformity start) | Federal §168(k) rules as in effect for that tax year | Add-back required. Iowa's pre-repeal rules applied — review separately |
| Before the 2020 rolling-conformity start | Federal §168(k) rules as in effect for that tax year | Iowa was on a static IRC date (2018-03-24) through 2019 — treatment may differ further from current federal law |
| Corporate vs. individual | Not applicable | No split — same repeal covers both §422.7 (individual) and §422.35 (corporate) |
| Federal usability of the deduction | Subject to passive activity, at-risk, basis, and business-interest limits | Same federal limits govern the federal deduction; Iowa's conformity (or lack of it) applies independently by placed-in-service date |
Sources: Iowa Code §422.3(5), Iowa Code §422.7, IRC §168(k). Federal bonus figures reflect current law; eligibility depends on acquisition and placed-in-service dates and elections.
Illustrative numbers: an Iowa single-family rental placed in service in 2023 or later
Using the single-family residential (SFR) band we publish — 9–32% of depreciable basis reclassified into 5/7/15-year property, 16% representative — on a property priced between $250,000 and $650,000, with a 20% residential land allocation, and 100% federal bonus depreciation for eligible components under current law:
| Line item | Federal | Iowa (PIS 2023-01-01+) |
|---|---|---|
| Purchase price band | $250,000–$650,000 | Same property |
| Depreciable basis (20% land allocation) | $200,000–$520,000 | Same basis, no adjustment |
| Reclassified to 5/7/15-yr (9–32% of basis) | $18K–$165K | Same amount flows through |
| Year-1 treatment | $18K–$165K deducted (100% bonus, if eligible) | Same $18K–$165K deducted; no Iowa add-back |
| Marginal tax rate | Up to 37% | Iowa individual or corporate income tax rate (verify current year with the Iowa Department of Revenue) |
| Illustrative Year-1 federal tax savings on reclassified components | ~$6,660–$61,570 (37% × $18K–$165K) | Full conformity; the same deduction reduces Iowa taxable income in Year 1 too |
Figures are illustrative and use the site's published SFR reclassification band; your result depends on your basis, land allocation, bracket, component mix, eligibility, and — as explained above — the property's placed-in-service date. Whether the full federal deduction is usable in the current year still depends on your passive-loss, at-risk, basis, and business-interest situation. This table assumes a placed-in-service date of 2023-01-01 or later; a pre-2023 property follows different Iowa rules.
See a sample cost segregation report
Look at exactly what your Iowa study delivers: the component-by-component 5/7/15-year schedule, the Form 4562-ready numbers, and the documentation your CPA files. Real reports are our best answer to "is this legit?"
Forms your CPA files for an Iowa property
For an Iowa property placed in service 2023-01-01 or later, the workflow is straightforward pass-through:
- Federal Form 4562: depreciation and amortization, including the §168(k) bonus deduction on eligible reclassified components. Flows to Schedule E (rental) or Schedule C (active business).
- Schedule E (or Schedule C): the accelerated federal deduction reduces federal taxable income in Year 1, subject to the federal passive-loss, at-risk, basis, and business-interest limits.
- Iowa individual or corporate income tax return: no add-back for property placed in service 2023-01-01 or later — the federal figure flows through directly, per the repeal of Iowa Code §422.7 and §422.35's former add-back subsections.
- Form 3115 §481(a) section: included only if this is a federal lookback method change — and for Iowa, only warrants a closer look if the underlying property's placed-in-service date is before 2023-01-01 (see below).
The reclassified schedule is the same engineered output for both books when the placed-in-service date is 2023-01-01 or later; the Iowa return simply carries the federal figure through unchanged.
Form 3115 lookback on an Iowa property
If the property was placed in service in a prior tax year and depreciation was reported using a non-segregated method, a federal Form 3115 (Application for Change in Accounting Method) may allow a current-year §481(a) catch-up adjustment for the accelerated depreciation you missed, generally without amending prior returns. This is often the single biggest acceleration mechanism in cost segregation. Any catch-up dollars are illustrative and depend on placed-in-service date, prior depreciation claimed, bonus eligibility, land allocation, and component mix.
For Iowa, this is exactly the situation where the placed-in-service-date rule matters most: if the property was placed in service on or after 2023-01-01, the catch-up flows through with no Iowa add-back regardless of the tax year the Form 3115 is actually filed. If the property was placed in service before 2023-01-01, the Iowa treatment follows the older add-back rules in effect at that time — confirm this separately before assuming full conformity.
See our full Form 3115 cost segregation guide for federal mechanics, partnership and LLC pass-through treatment, and timing rules.
Should you do cost segregation in Iowa?
Yes, and for property placed in service 2023-01-01 or later, the math is as clean as it gets — full conformity at both levels:
- The full federal Year-1 bonus is intact, and for modern property, Iowa adds no reduction on top of it — the federal figure flows straight through. How much you use in the current year still depends on your passive-loss, at-risk, basis, and business-interest situation.
- The Form 3115 lookback still captures missed federal years. If the property was placed in service in a prior year and depreciated without cost segregation, the federal §481(a) catch-up may be available, generally without amending prior returns.
- Confirm the placed-in-service date before promising the modern answer — the single most common way to get Iowa wrong is to apply "Iowa conforms" to a pre-2023 property without checking which rules were in effect when that specific property was placed in service.
The nuance to flag with your CPA is date-sensitivity, not complexity: for a straightforward purchase closing today, the answer is simply "full conformity." For a lookback study reaching into 2022 or earlier, the Iowa-level treatment needs its own check against the property's actual placed-in-service date.
Frequently asked
Does Iowa allow bonus depreciation?
Yes, for property placed in service on or after January 1, 2023. Iowa's bonus-depreciation add-back subsections were repealed retroactively to that date, and Iowa has had rolling Internal Revenue Code conformity since tax years beginning January 1, 2020. An individual or corporate taxpayer claims the same federal §168(k) bonus depreciation deduction (100% may apply to qualified property acquired and placed in service after January 19, 2025, subject to eligibility and election rules) on the Iowa return, with no add-back.
What date actually controls Iowa's answer — the tax year I'm filing, or something else?
The placed-in-service date of the property, not the tax year of the return. This is the detail a quick summary is most likely to get wrong. Iowa's repeal is retroactive to property placed in service on or after 2023-01-01 — so a property placed in service in, say, March 2023 gets full conformity even though the repeal legislation itself was enacted later, and a Form 3115 catch-up claimed in a later tax year still looks back to when the underlying property was placed in service, not to the year the catch-up return is filed.
What if my property was placed in service before 2023?
It is subject to different, older rules, and you should not assume today's full-conformity answer applies. Iowa required a bonus-depreciation add-back for property placed in service before 2023-01-01. Before that, Iowa was on a static Internal Revenue Code conformity date (2018-03-24) through 2019, rather than rolling conformity — meaning even the definition of "qualified property" and the bonus percentage available could differ from current federal law for that vintage of property. A lookback study or Form 3115 catch-up touching pre-2023 property needs its own review; do not extend the "Iowa conforms" answer backward to it.
Does the repeal apply to both individuals and corporations?
Yes. The repeal covers both the individual add-back provisions referenced in Iowa Code §422.7 and the parallel corporate add-back subsections in §422.35. There is no individual/corporate split in the modern answer — both taxpayer types get full conformity for property placed in service 2023-01-01 or later.
Is cost segregation still worth it in Iowa?
Yes, for property placed in service in 2023 or later — the federal Year-1 bonus flows straight through with no Iowa add-back to plan around, so the acceleration is fully available at both the federal and Iowa level. For older property, the study is generally still worthwhile at the federal level, but the Iowa-level treatment (and whether an add-back applied in the year the property was placed in service) needs its own review before promising a client the modern conformity answer.
Can I use Form 3115 on an Iowa property I bought years ago?
Often, yes, at the federal level, and the placed-in-service date drives the Iowa answer here too. If the property was placed in service on or after 2023-01-01 and depreciation was reported using a non-segregated method, a federal Form 3115 (Application for Change in Accounting Method) may allow a current-year §481(a) catch-up, generally without amending prior returns, and Iowa conforms to the catch-up with no add-back. If the property was placed in service before 2023-01-01, the Iowa treatment follows the older add-back rules that applied at that time — this should be confirmed separately rather than assumed.
What does an Iowa cost segregation study rely on for its numbers?
The study reclassifies building components into IRS-recognized MACRS class lives (5, 7, and 15-year) per Rev. Proc. 87-56, using an engineering-based methodology that follows the IRS Cost Segregation Audit Techniques Guide (Publication 5653). The reclassified components may then qualify for federal §168(k) bonus depreciation on the federal return (100% for qualified property acquired and placed in service after January 19, 2025, subject to eligibility and election rules), and Iowa conforms to that bonus without an add-back for property placed in service 2023-01-01 or later. The engine ships our own calibrated, nationally-recognized construction cost data.