Missouri Bonus Depreciation: Conforms, Despite an Add-Back That Looks Current.
Missouri conforms to federal §168(k) bonus depreciation: Missouri adjusted gross income starts from federal AGI, and the federal deduction flows through to the Missouri return. A §168 add-back does exist in the statute — but it reaches only property purchased between July 1, 2002 and July 1, 2003, not a current purchase.
Reviewed by Cost Seg Smart Editorial Team · Last verified against Mo. Rev. Stat. §143.121 — Missouri adjusted gross income
The 30-second answer: Missouri conforms to federal §168(k) bonus depreciation. Missouri adjusted gross income starts from federal AGI, and the federal §168(k) deduction flows through to the Missouri return — there is no current-year add-back to plan around.
The decoy most summaries miss: Mo. Rev. Stat. §143.121.2(3) does add back a §168 deduction, and a keyword search for "Section 168" finds it and would wrongly suggest Missouri decouples today. Read the actual condition: it applies only "to the extent the amount deducted relates to property purchased on or after July 1, 2002, but before July 1, 2003" — a one-year window from the Job Creation and Worker Assistance Act of 2002. Unless your property was purchased in that specific window, it does not apply to you.
On a representative Missouri single-family rental (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, and because Missouri conforms, that deduction carries through to the Missouri return unmodified.
Federal vs Missouri, Side by Side
For an individual investor's cost-segregation-reclassified components:
| Tax provision | Federal (IRC) | Missouri |
|---|---|---|
| Bonus depreciation under §168(k) | 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 | Flows through unmodified. Missouri AGI starts from federal AGI and adopts the federal §168(k) deduction for a current purchase |
| The §143.121.2(3) add-back | Not applicable | Historical only. Applies solely to property purchased July 1, 2002 – July 1, 2003; does not reach a property placed in service today |
| Recovery of the reclassified basis | 100% bonus in Year 1 for eligible components, if elected | Same Year-1 treatment; no separate Missouri recovery schedule |
| Federal usability of the deduction | Subject to passive activity, at-risk, basis, and business-interest limits | Same federal limits govern the deduction that then flows through to Missouri |
| MACRS asset class lives | 5 / 7 / 15 / 27.5 / 39 yr per Rev. Proc. 87-56 | Same class lives; Missouri does not recompute depreciation against them |
Source: Mo. Rev. Stat. §143.121.2(3); IRC §168(k). Federal bonus figures reflect current law; eligibility depends on acquisition and placed-in-service dates and elections.
Checked because it looked like an add-back — and isn't
Search "Missouri bonus depreciation" against the statute text and Mo. Rev. Stat. §143.121.2(3) surfaces immediately: it names "Section 168" and describes an amount to be "added" back to Missouri income. Read only the first half of the sentence, and Missouri looks exactly like a decoupled state — the same shape as Arizona's or Georgia's add-back.
Read the full condition and the resemblance ends: the add-back applies only "to the extent the amount deducted relates to property purchased on or after July 1, 2002, but before July 1, 2003." That is a one-year window, tied to the bonus depreciation Congress enacted in the Job Creation and Worker Assistance Act of 2002 — not a standing, current-year decoupling provision. A property purchased today, in 2026, does not fall inside that window, so the add-back simply does not apply to it.
This is exactly the trap a keyword-matching summary falls into: the provision exists, it is real, and it is genuinely a §168 add-back — it is just twenty-plus years out of date for anything being purchased now. If your CPA or a search result raises this citation, the correct response is not to dismiss it, but to confirm the purchase date on the property in question. Unless that date falls between July 1, 2002 and July 1, 2003, the add-back has no effect on your Missouri return.
Outside that narrow historical window, Missouri simply conforms: Missouri adjusted gross income starts from federal AGI, and the federal §168(k) deduction — including 100% bonus depreciation on cost-segregation-reclassified components — flows through to the Missouri return, subject to the usual federal limits.
Illustrative numbers: a Missouri single-family rental
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, purchased in 2026 (outside the 2002-2003 add-back window):
| Line item | Federal | Missouri |
|---|---|---|
| Purchase price band | $250,000–$650,000 | Same property |
| Depreciable basis (20% land allocation) | $200,000–$520,000 | Same basis |
| Reclassified to 5/7/15-yr (9–32% of basis) | $18K–$165K | Same reclassified amount |
| Year-1 treatment | $18K–$165K deducted (100% bonus, if eligible) | Same $18K–$165K flows through — no Missouri add-back applies |
| Marginal tax rate | Up to 37% | Missouri individual income tax rate (verify current year with the Missouri Department of Revenue) |
| Illustrative Year-1 federal tax savings on reclassified components | ~$6,660–$61,570 (37% × $18K–$165K) | Same deduction reduces Missouri taxable income, since Missouri conforms |
Figures are illustrative and use the site's published SFR reclassification band; your result depends on your basis, land allocation, bracket, component mix, and eligibility. Whether the full federal deduction is usable in the current year still depends on your passive-loss, at-risk, basis, and business-interest situation. If the property in question was purchased between July 1, 2002 and July 1, 2003, confirm with your CPA whether the historical §143.121.2(3) add-back applies to it.
See a sample cost segregation report
Look at exactly what your Missouri 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 a Missouri property
For an individual Missouri investor, the workflow is simpler than in a decoupled state, because the same federal figure carries through to the state return:
- 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.
- Missouri Form MO-1040: Missouri adjusted gross income starts from federal AGI, and the federal §168(k) deduction carries through unmodified — unless the property was purchased between July 1, 2002 and July 1, 2003, the narrow historical add-back window under §143.121.2(3).
- Form 3115 §481(a) section: included only if this is a federal lookback method change on a property placed in service in a prior year (see below).
The reclassified schedule is the same engineered output regardless of state; for Missouri, there is no separate state-level recomputation to layer on top of it.
Form 3115 lookback on a Missouri 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.
The federal §481(a) catch-up is the primary lever, and it remains subject to the federal passive-loss, at-risk, and basis limits. Because Missouri conforms, the catch-up amount carries through to the Missouri return the same way a current-year deduction does — the one exception being the historical July 2002–2003 purchase window described above, which would not affect most lookback studies given how long ago it closed.
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 Missouri? Yes.
Missouri's conformity means there is no state-level wrinkle to plan around, which is not the same as saying a study has nothing to add. The math favors doing the study, for three reasons:
- The full federal Year-1 bonus flows straight through. Missouri does not reduce, recompute, or defer it. How much you use in the current year still depends on your passive-loss, at-risk, basis, and business-interest situation.
- The §143.121.2(3) add-back is not a live concern for a current purchase. It applies only to property purchased between July 1, 2002 and July 1, 2003 — confirm that date on any property before assuming otherwise, but for the overwhelming majority of Missouri investors it simply does not apply.
- The study reclassifies basis regardless of state. The 5/7/15-year components that qualify for bonus depreciation exist in the building whether it sits in Missouri, Texas, or California; Missouri conformity just means the resulting federal benefit is not diluted at the state level.
The one thing worth flagging with your CPA is precisely the purchase date, if a citation to §143.121 comes up in review — not because Missouri decouples, but because confirming the date is what rules the historical add-back out.
Frequently asked
Does Missouri allow bonus depreciation?
Yes. Missouri conforms to federal §168(k) bonus depreciation. Missouri adjusted gross income starts from federal adjusted gross income, and there is no current-year add-back that reaches property placed in service today, so the federal bonus depreciation deduction (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) flows through to the Missouri return without modification.
Doesn't Mo. Rev. Stat. §143.121 contain a §168 add-back? Does that mean Missouri decouples?
It contains an add-back, but not one that applies to a current purchase — and this is the fact a keyword search gets wrong. §143.121.2(3) adds back a §168 deduction only "to the extent the amount deducted relates to property purchased on or after July 1, 2002, but before July 1, 2003." That is a one-year window tied to the bonus depreciation Congress enacted in the Job Creation and Worker Assistance Act of 2002, not a standing decoupling provision. Unless your property was purchased in that specific 2002-2003 window, this add-back does not apply to you.
Why does a keyword search suggest Missouri decouples from bonus depreciation?
Because §143.121.2(3) literally names "Section 168" and "deducted," so a text search for those terms surfaces it as if it were a general add-back. Reading the actual condition attached to it — the 2002-07-01 to 2003-06-30 purchase window — shows it is historical and narrow, not a current-year modification. This is precisely the kind of provision that looks decoupled from a search snippet and is not, once you read the full sentence.
What happens on my Missouri return with a current cost segregation study?
The federal §168(k) bonus depreciation deduction on your reclassified 5-, 7-, and 15-year components flows through to Missouri income unmodified, because Missouri starts from federal AGI and no current-year §168 add-back applies. Subject to the usual federal passive-activity, at-risk, basis, and business-interest limits that govern how much of the deduction you can use in the current year, the accelerated deduction reduces Missouri taxable income the same way it reduces federal taxable income.
Is cost segregation worth it in Missouri?
Yes, and Missouri is one of the more straightforward states for it: there is no state-level add-back to plan around. The federal Year-1 bonus is the dominant driver, and because Missouri conforms, the Missouri-level benefit tracks the federal benefit directly rather than being recomputed, added back, or spread over a different schedule. Whether the full federal deduction is usable in the current year still depends on your passive-activity, at-risk, basis, and business-interest situation.
Can I use Form 3115 on a Missouri property I bought years ago?
Often, yes, at the federal level. 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 for the accelerated depreciation you missed, generally without amending prior returns. Any catch-up dollars are illustrative and depend on placed-in-service date, prior depreciation, bonus eligibility, land allocation, and component mix. Because Missouri conforms, the catch-up flows through to the Missouri return the same way the current-year deduction does — unless the property itself was purchased in the narrow 2002-07-01 to 2003-06-30 window described above.
What does a Missouri 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 because Missouri conforms, that same deduction flows through to the Missouri return. The engine ships our own calibrated, nationally-recognized construction cost data.
Related guides
- Bonus depreciation by state: overview
- All 50 states: conformity reference table
- Nevada bonus depreciation (no income tax)
- Washington bonus depreciation (no income tax)
- Minnesota bonus depreciation (decoupled, 80% add-back)
- Form 3115 cost segregation lookback: §481(a) mechanics
- What is cost segregation: the full primer
- Sample cost segregation reports