Cost Segregation Study in Ohio

Ohio completed its move to a flat individual income tax in 2026, dropping the top rate to 2.75%. Combined with the Business Income Deduction, which exempts the first $250,000 of business income outright, Ohio is now one of the least expensive income tax states in which to operate a profitable pass-through.

Ohio also applies the most distinctive bonus depreciation rule in the country. It is known as the 5/6 add-back, and it produces a state depreciation schedule that looks like nothing else. Understanding it is the difference between an Ohio cost segregation projection that is right and one that is off by a factor of five.

How Ohio Income Tax Interacts With Federal Strategy

For tax year 2026 Ohio applies a flat 2.75% rate to nonbusiness income above $26,050, completing the multi-year flattening enacted in HB 96. Ohio joined the group of single-rate states with that change.

Business income is treated separately and more favorably. Ohio's Business Income Deduction exempts the first $250,000 of business income from tax entirely for joint and single filers, and $125,000 for married filing separately. Business income above that threshold is taxed at a flat 3%.

That structure creates a threshold effect that a cost segregation study can be aimed at. If your Ohio business income is near or modestly above $250,000, a study that pushes the number below the BID threshold eliminates Ohio tax on that income entirely rather than merely reducing it. That is a step function, not a linear benefit, and it is worth sizing the study around deliberately.

Separately, the Commercial Activity Tax applies to gross receipts with an exclusion of $6 million effective 2025. Most single-property real estate entities fall well under the exclusion.

Ohio Pass-Through Entity Tax

Ohio's elective pass-through entity tax was enacted in Senate Bill 246, signed June 14, 2022. Partnerships, LLCs taxed as partnerships, and S corporations may elect to pay Ohio tax at the entity level on Form IT 4738.

The rate was 5% for tax year 2022 and is 3% for tax years after 2022, including 2026. The rate is fixed at 3% and does not track the individual rate structure, which is a common point of confusion. Owners receive a fully refundable Ohio credit for their share of the entity-level tax.

One 2026 change deserves a calendar entry. Beginning with tax year 2026, the second and third quarter estimated payment due dates move up by one month, to June 15 and September 15 respectively. First and fourth quarter dates remain April 15 and January 15. Entities that carried forward last year's payment calendar will underpay.

The Ohio PTET interacts with the Business Income Deduction in a way that requires modeling. The BID already exempts the first $250,000 of business income, so for smaller pass-throughs the PTET may be capturing a federal deduction on tax the owner would not have paid anyway. The election is most clearly valuable for entities with income well above the BID threshold.

Ohio Depreciation Conformity

Ohio requires an add-back of federal bonus depreciation, and the amount depends on the taxpayer's circumstances. The general rule, applied when the taxpayer has positive federal adjusted gross income, is the 5/6 add-back: five-sixths of the federal bonus depreciation deduction is added back in the placed-in-service year, and the added-back amount is then deducted in equal installments over the following five years.

Two variations apply. If federal adjusted gross income is negative for the year, the taxpayer adds back the entire bonus depreciation deduction and deducts one-sixth of the add-back over the following six years. And a more favorable 2/3 add-back applies where the taxpayer's business increased Ohio employer withholding by at least 10% over the prior year, which is designed to reward hiring.

The practical result is that Ohio permits one-sixth of the federal bonus deduction immediately in the ordinary case, then returns the rest over five years. Compared with a state like California that allows none of it, Ohio's regime is considerably gentler. Compared with Colorado, which allows all of it, it is a real deferral.

Cost Segregation Considerations Specific to Ohio

Ohio's cost segregation planning is driven by the interaction of three thresholds.

First, the 5/6 add-back means you should never model an Ohio study by simply applying the state rate to the federal deduction. On a $600,000 first-year federal bonus deduction, Ohio allows $100,000 in year one and $100,000 in each of the next five years. At a 3% business income rate the annual amounts are modest, but the timing matters for anyone using the study to manage a specific year's liability.

Second, the negative-FAGI variation is a trap. Investors frequently use a cost segregation study precisely to drive income negative. Doing so switches Ohio from the 5/6 add-back to a full add-back with a six-year recovery, which is the least favorable version of the rule. If your Ohio position is close to the line, the state result is meaningfully better if federal AGI stays positive. That is an unusual planning consideration and it is specific to Ohio.

Third, the withholding-growth exception is genuinely usable by operating businesses. An Ohio business that grew payroll enough to raise Ohio employer withholding 10% year over year qualifies for the 2/3 add-back instead of 5/6, which nearly doubles the immediate Ohio deduction. Businesses that are both expanding headcount and placing significant property in service should check whether they cleared the 10% threshold before filing.

Beyond the depreciation mechanics, Ohio's older industrial and commercial building stock produces high reclassification percentages on engineering-based studies. Converted warehouses, older multifamily, and legacy manufacturing space carry substantial specialty electrical, plumbing, and site improvements that sit in the 5 and 15-year classes. Ohio investors buying value-add property in Columbus, Cleveland, and Cincinnati routinely see reclassification well above the levels typical of newer suburban product.

Working With AE Tax Advisors in Ohio

AE Tax Advisors works with real estate investors, business owners, and high-income professionals across Ohio and all fifty states. We are a licensed CPA and IRS Enrolled Agent practice based in Billings, Montana, and we handle the engineering-based cost segregation study, the Ohio conformity adjustments, the entity structuring, and the return preparation as one engagement rather than three vendors who do not talk to each other.

That matters more in Ohio than it does in a state with simple conformity. A cost segregation provider who delivers a federal-only report leaves you and your preparer to work out the Ohio treatment after the fact, which is where the errors happen. We model the federal and Ohio outcome together before the study is commissioned, so you know what the number actually is on both returns before you spend anything.

Related reading: the complete guide to cost segregation, our cost segregation study service, short-term versus long-term rental tax treatment, lookback studies and Form 3115, and multi-state tax planning.

Ohio tax rates, pass-through entity tax rules, and depreciation conformity provisions described on this page reflect law in effect as of August 2026 and are provided for general information only. State conformity changes frequently and often retroactively. Nothing here is tax advice for your situation, and no client relationship is created by reading it. Talk to us about your facts before acting.