Arizona is one of a small number of states with a flat individual income tax, a rate lawmakers cut to 2.5% in 2023 — the lowest flat rate of any state that taxes income at all. That is a favorable backdrop for rental owners, and Arizona adds a second advantage many owners do not expect: for individual and pass-through owners, the state effectively follows the federal government's 100% bonus depreciation rules. Investors who own property in the state's established short-term-rental markets — Phoenix and Scottsdale, Sedona, Tucson, Flagstaff, and Lake Havasu City — capture the full federal acceleration and generally the same first-year deduction on their Arizona return; their CPA just reports a matching addback and subtraction.
Apex Reserve Group is an Irvine, California-based firm that performs engineering-based cost segregation studies for real estate investors nationwide, including throughout Arizona. Everything on this page is general educational information, not tax or legal advice — confirm how these rules apply to your specific property and return with your own CPA.
Why Cost Segregation Pays Off in Arizona
Arizona moved to a flat 2.5% individual income tax rate in 2023, replacing its old graduated brackets and giving the state the lowest flat income-tax rate in the nation among states that tax income. That single fact changes how much weight the federal half of a cost segregation study carries for an Arizona property owner, relative to an investor in a high-tax state.
Here is the state-specific detail that matters most, and the one most worth confirming with your CPA: for individuals and pass-through owners, Arizona effectively follows federal bonus depreciation under Internal Revenue Code Section 168(k). Arizona Revised Statutes 43-1021 requires you to add back all federal depreciation, but 43-1022 then lets you subtract Arizona depreciation computed as if bonus were the full federal Section 168(k) amount. The two entries cancel out, so the 100% bonus carries through to your Arizona return. Only C corporations are decoupled; they must recompute depreciation as if bonus had not been claimed. Arizona's 2026 conformity legislation (HB 4168, signed into law in June 2026) moved the state's IRC date to January 1, 2026, which picks up the One Big Beautiful Bill Act's 100% rate, and added a separate addback only for the new Section 168(n) qualified production property allowance, which does not apply to rental buildings.
In practice, this means the accelerated first-year write-off from a cost segregation study appears in full on your federal return and, for individual and pass-through owners, on your Arizona return as well. Because Arizona's rate is only 2.5% flat, the state share of that benefit is comparatively modest next to the federal benefit, which is calculated at your regular federal bracket, up to 37%. Add Arizona's low property tax burden — an effective rate of roughly 0.4% to 0.6%, well under the national average of about 0.9% to 1.1% — and a deep bench of short-term-rental markets in Phoenix and Scottsdale, Sedona, Tucson, Flagstaff, and Lake Havasu City, and the overall carrying cost of Arizona rental property is low even before cost segregation enters the picture.
How a Cost Segregation Study Works
A cost segregation study is an engineering-based review of a building's construction records, appraisal, and site conditions. Rather than depreciating an entire residential rental over 27.5 years (39 years for commercial property) as a single asset, the analyst separates out components — flooring, cabinetry, built-in appliances, specialty electrical and plumbing, decking, fencing, and land improvements such as landscaping and paving — that the tax code actually treats as 5-, 7-, or 15-year property.
Under the One Big Beautiful Bill Act, signed into law in July 2025, Congress permanently restored 100% bonus depreciation for qualifying property acquired and placed in service after January 19, 2025 (or, for self-constructed property, where construction began after that date). That means any component a study reclassifies into the 5-, 7-, or 15-year categories can, on the federal return, be deducted in full in the year it is placed in service rather than depreciated gradually over decades. One nuance worth flagging for your CPA: property acquired under a binding contract signed before January 19, 2025 but placed in service later can instead remain subject to the prior law's phase-down schedule, so the placed-in-service date alone does not always control — the acquisition date matters too.
An Arizona Cost Segregation Example
The following is a hypothetical for illustration only, not a projection for any actual property. Your results depend on your property's cost basis, its components, and your personal tax situation.
Suppose an investor buys a short-term rental near Sedona for $600,000. After allocating $100,000 to land, which is never depreciable, the depreciable building basis is $500,000.
- Without cost segregation: the full $500,000 depreciates straight-line over 27.5 years, for a deduction of roughly $18,200 per year.
- With a cost segregation study: an engineering review identifies, hypothetically, $125,000 of components — flooring, appliances, specialty electrical, decking, and landscaping — that qualify for 5-, 7-, or 15-year treatment.
- On the federal return: under 100% bonus depreciation, that full $125,000 could be deducted in year one instead of over decades.
- On the Arizona return: an individual or pass-through owner adds back the federal depreciation and then subtracts Arizona depreciation computed with the full federal bonus, so the same $125,000 is generally deductible in year one in Arizona too. Given Arizona's 2.5% flat rate, the state savings are modest in dollar terms next to the federal deduction.
Again, these numbers are illustrative only. An actual study would itemize your specific property, and your CPA would apply your real federal and Arizona tax figures.
Already Own Your Arizona Property? The Look-Back Study
If you already own Arizona rental property and have been depreciating it on a standard schedule, you have not missed your window. A look-back study applies cost segregation to a property after it has already been placed in service. Rather than amending every prior-year return, your CPA files IRS Form 3115 (Application for Change in Accounting Method), which converts the difference between what was actually depreciated and what should have been depreciated into a single Section 481(a) adjustment — claimed as a one-time catch-up deduction in the current tax year, with no amended returns required. On the Arizona side, the same matching addback and subtraction described above generally carries that catch-up through to the state return for individual and pass-through owners; confirm the Arizona reporting with your CPA.
Who Should Consider Cost Segregation in Arizona
Cost segregation tends to make the most sense for:
- Short-term rental and Airbnb hosts in Arizona's established vacation-rental markets, including Phoenix and Scottsdale, Sedona, Tucson, Flagstaff, and Lake Havasu City.
- Long-term rental property owners who want to accelerate federal depreciation even without using the short-term-rental strategy described below.
- Recent buyers, or owners who have completed a major renovation, since a new cost basis or significant improvement creates fresh components to classify.
- High-earning W-2 or 1099 taxpayers exploring the short-term-rental material-participation strategy: if a property's average guest stay is 7 days or less and the owner materially participates in operating it, the rental can be treated as non-passive under IRS rules, which may let depreciation losses from cost segregation offset active income. This hinges on meeting specific material-participation and average-stay tests, so it should be planned with a CPA before the tax year closes.