Cost Segregation on Net Lease Deals: How the Tax Math Actually Works

TL;DR

Cost segregation is an IRS-recognized engineering study that breaks a commercial building's depreciable basis into multiple asset classes — 5-year, 7-year, 15-year, and 39-year property — instead of the default "all 39-year." The shorter-life portions can be depreciated faster, generating larger tax deductions in the early years of ownership. Combined with bonus depreciation (which lets you take a percentage of the shorter-life depreciation in year 1), the cash benefit on a typical net lease asset can be material — particularly for buyers who can use the deductions against passive or active income.

For brokers, the talking point is: cost segregation often pays for itself many times over in year 1 alone, and is one of the few legitimate "free returns" in commercial real estate.

How Depreciation Normally Works on a Commercial Building

When a buyer acquires a commercial property, the IRS requires the basis to be allocated between land (not depreciable) and building (depreciable). The building is then depreciated straight-line over 39 years for non-residential real property under IRS Code Section 168.

So a buyer paying $5M for a building (assume $1M land, $4M building):

• Year-1 depreciation deduction: $4,000,000 ÷ 39 ≈ $102,564
• Federal tax benefit at 37% marginal rate: ≈ $37,949 in year-1 cash

That's the default. Without any further work, that's all the buyer gets.

What Cost Segregation Does

A cost segregation study is performed by an engineering firm that has tax expertise. The engineer physically inspects the property (or works from drawings + a site visit) and breaks the $4M building basis into IRS-recognized categories:

• 5-year property (e.g., specific plumbing, certain electrical for tenant use, security systems, certain finishes)
• 7-year property (e.g., decorative elements, certain flooring, specific equipment)
• 15-year property (e.g., site improvements: paving, landscaping, parking lot lighting, fencing)
• 39-year property (the building shell — what's left after the above is allocated out)

A typical cost segregation result for a freestanding net lease retail building:

The exact percentages depend on building type, age, and the engineer's analysis. New build-to-suit retail tends to be on the higher end of accelerated allocation; older buildings on the lower end.

The Bonus Depreciation Layer

Bonus depreciation (under IRS Code Section 168(k)) allows a buyer to expense a percentage of qualifying short-life property in the year of acquisition rather than depreciating it over the full 5/7/15-year life.

The bonus depreciation percentage has been phasing down:

• 2017-2022: 100% bonus depreciation
• 2023: 80%
• 2024: 60%
• 2025: 40%
• 2026: 20%
• 2027 and after: 0% (under current law; potentially extended by future legislation)

So for a 2026 acquisition, the year-1 bonus depreciation rate is 20% of the qualifying 5/7/15-year property.

Worked Example — $5M Net Lease Deal

Let's run the math on a $5M acquisition closing in 2026.

Assumptions:

• Purchase price: $5,000,000
• Land allocation: $1,000,000 (20%)
• Building allocation: $4,000,000 (80%)
• Cost segregation result: 12% short-life ($480,000 split between 5/7/15-year), 68% remaining 39-year ($2,720,000), and 20% to 5/7/15 net of overlap with land — let's use simplified $400,000 in 15-year, $80,000 in 5/7-year for this example
• Buyer marginal tax rate: 37% federal + 5% state = 42%
• Bonus depreciation: 20% (2026 rate)

Year-1 Depreciation Without Cost Segregation

• $4,000,000 ÷ 39 = $102,564 deduction
• Cash tax benefit: $102,564 × 42% = $43,077

Year-1 Depreciation With Cost Segregation

For the 15-year property ($400,000):

• 20% bonus depreciation: $80,000
• Remaining $320,000 depreciated straight-line over 15 years: $21,333 in year 1
• 15-year property year-1 deduction: $101,333

For the 5/7-year property ($80,000):

• 20% bonus depreciation: $16,000
• Remaining $64,000 depreciated straight-line over 5 years (using simplified, actual is MACRS): $12,800 in year 1
• 5/7-year property year-1 deduction: $28,800

For the 39-year property ($3,520,000):

• $3,520,000 ÷ 39 = $90,256

Total year-1 deduction with cost seg: $220,389

Cash tax benefit: $220,389 × 42% = $92,563

Incremental cash savings vs. default: $92,563 - $43,077 = $49,486 in year 1

Cost of the Cost Segregation Study

A cost segregation study on a $5M asset typically runs $4,000-$8,000 from a reputable provider. ROI in year 1 alone is roughly 6-10x the study cost.

Where Cost Segregation Makes Sense (and Where It Doesn't)

Strong fit:

1. Active or passive income to absorb the deductions

The depreciation deductions only have cash value if they reduce taxable income. Buyers who have other passive real estate income, or who actively run real estate businesses (real estate professional status under the IRS) and have active income to absorb deductions, get the most benefit.

1. High marginal tax rates

Buyers in the 37% federal bracket plus high-tax states (CA, NY, NJ, MA) get more benefit per dollar of deduction. Buyers in 24% bracket states with no state income tax get materially less.

1. Long expected hold periods

While cost segregation accelerates deductions, the IRS requires depreciation recapture at sale — if you take accelerated depreciation, you may owe more tax at the time of sale. Cost segregation is most valuable for buyers planning long holds (10+ years) or those planning to use a 1031 exchange to defer recapture.

1. New construction or recently renovated buildings

Higher allocations to 5/7/15-year property; cleaner engineering analysis.

Weak fit:

1. Buyers with no other income to absorb the deductions

A retiree who buys a single net lease asset and has $40k of social security income can't fully use $100k+ of depreciation deductions in year 1. The deductions carry forward as passive losses, but the time value is lost.

1. Short hold periods

If the buyer plans to sell in 2-3 years, the recapture math may eliminate most of the up-front benefit. Worth running the analysis with a tax advisor.

1. Older, simpler buildings

A 1970s-era CVS box has fewer separable improvements — the cost seg study may identify only 5-8% short-life, vs 15-20% for a modern build-to-suit.

The Recapture Math at Sale

When a property is sold, the IRS requires the buyer to "recapture" any depreciation taken at higher than the standard rate. The recapture rules:

• Section 1245 recapture (5/7/15-year property): recaptured at ordinary income rates (up to 37% federal) on the depreciation taken
• Section 1250 recapture (39-year property): recaptured at a maximum 25% federal rate on the depreciation taken

So a buyer who took $400k of accelerated depreciation in year 1 via cost seg, then sells in year 5, owes recapture tax on the depreciation taken — but at the lower 25% rate for the 39-year portion and at the buyer's ordinary income rate for the 5/7/15-year portion.

The net benefit of cost segregation is typically positive even after recapture, because:

1. The deductions create cash flow earlier (time value of money)
2. The marginal rate at sale may be lower than the marginal rate during ownership
3. A 1031 exchange defers the recapture indefinitely

What Brokers Should Say to Buyers

You're not a tax advisor and shouldn't give specific tax advice. But you can credibly position cost segregation as:

"On a $5M deal like this, cost segregation typically generates $40-60k of incremental year-1 tax benefit on top of standard depreciation. The study runs $4-8k. Worth talking to your tax advisor about whether you can use the deductions — for buyers with other real estate income, this is often a meaningful boost to year-1 IRR."

For very-small-deal buyers (under $1.5M), the math is tighter — the study cost eats more of the benefit. For deals above $3M with active investors, it's usually a clear win.

Bonus Depreciation Phase-Down Implications for 2026

The phase-down to 20% bonus depreciation in 2026 (from 100% in 2017-2022) materially reduces the year-1 boost. A buyer in 2026 gets roughly 80% less year-1 cash benefit from the bonus depreciation portion than a buyer in 2022 would have gotten on the same asset.

Why this matters:

• Asset values priced when bonus depreciation was 80-100% included an implicit tax-benefit premium
• As bonus phases out, that premium fades, which is one of the secondary headwinds on retail net lease cap rates over the past few years (alongside the Treasury rate move)
• For 2026 buyers, the tax math should be re-run at 2026 rates, not legacy assumptions from 2022-2023

For new construction sale-leaseback deals where the seller is also the developer, this also affects pricing — a 2026 deliverable that closes in 2026 gets less bonus depreciation than the same deal would have closed in 2022.

A Note on Real Estate Professional Status

Some buyers can qualify as real estate professionals under IRS Section 469(c)(7), which lets them use real estate losses (including cost-seg-driven depreciation) against active income, not just passive. The criteria:

• More than 50% of personal services in real estate trades or businesses, AND
• More than 750 hours per year in real estate activities

For buyers who qualify, this is a major unlock — depreciation deductions can offset W-2 income, business income, etc. For buyers who don't, the deductions are stuck against passive income (other rental income, etc.).

The election is on the buyer's tax return, not part of the deal — but it's worth knowing when talking with active real estate buyers vs passive investors.

Closing

Cost segregation isn't a tax loophole; it's an IRS-sanctioned approach that's been litigated and validated over decades. The phase-down of bonus depreciation has reduced its impact materially in 2026 vs 2022, but it remains one of the few free returns in net lease investing — particularly for high-tax-bracket buyers with sufficient income to absorb the deductions.

For brokers, the value-add is to mention it credibly when presenting deals to investors, not to pretend to be a tax advisor. Most buyers' CPAs already know about cost segregation, but reminding them at the LOI stage that the deal supports a study can shift buyer math materially in your favor.