Apartment buildings and multifamily properties are some of the best candidates for cost segregation studies. They start with a shorter base depreciation schedule (27.5 years vs. 39 years for commercial), they contain a high density of reclassifiable components per unit, and the per-unit multiplier effect means even small items — a $200 garbage disposal across 100 units — add up to meaningful reclassified basis.
With the OBBBA permanently restoring 100% bonus depreciation for qualifying property acquired and placed in service after January 19, 2025, multifamily investors can now deduct 25-35% of a building’s purchase price in year one. For a $5 million apartment building, that’s roughly $400,000-$600,000 in immediate tax savings at typical rates.
Here’s how cost segregation works for multifamily properties, what components get reclassified, how passive activity rules affect your ability to use the deductions, and what you need to know about the OBBBA’s changes.
Key Takeaways
- Multifamily properties typically yield 25-35% reclassification — higher than most commercial property types due to the per-unit multiplier effect
- The OBBBA permanently restored 100% bonus depreciation for qualifying assets placed in service after January 19, 2025 — making cost segregation more valuable than at any point in the past decade
- To use accelerated deductions against non-rental income, you generally need Real Estate Professional Status (REPS) or the short-term rental loophole — otherwise deductions are limited to passive income
- You can perform a retroactive “look-back” study on apartment buildings you already own — capturing missed depreciation on your current-year return via Form 3115, no amended returns needed
Why Apartment Buildings Are Ideal for Cost Segregation
Multifamily properties outperform most other real estate types in cost segregation studies for three reasons:
The per-unit multiplier
Every unit contains its own set of reclassifiable components — appliances, flooring, cabinetry, plumbing fixtures, light fixtures, dedicated electrical, countertops. A single dishwasher costs $500. Across 100 units, that’s $50,000 in 5-year property. Multiply this across every in-unit component and the reclassified basis grows rapidly.
The 27.5-year baseline advantage
Commercial properties start at 39-year depreciation. Apartment buildings start at 27.5 years. Cost segregation reclassifies components out of an already shorter baseline, meaning every dollar moved into 5-, 7-, or 15-year property represents even more acceleration relative to the default schedule.
Amenity-rich properties yield more
Pools, fitness centers, playgrounds, parking structures, clubhouses, laundry facilities, landscaping, and outdoor lighting all contain reclassifiable components. The more amenities a property has, the higher the reclassification percentage tends to be.
What Gets Reclassified in an Apartment Building
Real Example: $5M Apartment Building
Here’s how the math works for a 50-unit apartment complex acquired in 2026 for $5 million ($4.25M depreciable basis after land allocation), with both contract and placed-in-service dates after January 19, 2025.
Without cost segregation: You’d take approximately $154,500 in year-one depreciation (standard 27.5-year on the full building). With cost segregation + bonus: You take approximately $1,178,400. At a 35% tax rate, that’s roughly $358,000 in additional first-year tax savings from a study that typically costs $8,000-$12,000 for a 50-unit property.
The Passive Activity Rules: Can You Actually Use the Deductions?
This is where multifamily cost segregation gets nuanced. Generating a large depreciation deduction is one thing. Being able to use it against your other income is another. The passive activity rules under IRC §469 determine how you can use rental losses.
Three paths to using accelerated depreciation
Real Estate Professional Status
If you (or your spouse) qualify as a real estate professional — spending 750+ hours per year in real estate activities and more than half of personal services in real estate trades — all rental activity becomes non-passive. This means accelerated depreciation losses can offset W-2 income, business income, and other active income. This is the most powerful path for high-income investors with a spouse who manages properties full-time.
Short-Term Rental Loophole
If average guest stays are 7 days or less and you materially participate in the management, the property isn’t treated as a “rental activity” under §469. Instead, it’s a non-passive business activity — and losses can offset other income without REPS. This applies to furnished apartments, corporate housing, and vacation rentals. It doesn’t apply to traditional long-term apartment buildings.
Passive Activity Offset (Default)
If you don’t qualify for REPS or the STR loophole, accelerated depreciation losses can only offset other passive income — rental income from other properties, K-1 passive income from partnerships, etc. Unused passive losses carry forward indefinitely and release fully when you sell the property. This still has value — it shelters passive income and reduces taxes at disposition.
From our practice: The passive activity analysis should happen before you commission the cost segregation study — not after. If you can’t use the accelerated losses (no REPS, no passive income to offset, long-term hold with no near-term sale), the study might not produce current-year tax savings. We evaluate your specific tax situation as part of the feasibility analysis. Sometimes the right answer is to wait — and sometimes it’s to accelerate everything because the tax position is perfect. We give you the honest answer before you spend money on a study.
Syndication and Partnership Structures
For multifamily syndications, cost segregation benefits flow through the partnership to individual investors via Schedule K-1. The sponsor (GP) coordinates the study and structures the deal so limited partners (LPs) receive their share of the accelerated depreciation.
For Sponsors (GPs)
Commission the study at acquisition. Include projected depreciation in your investor projections. The study cost is a property-level expense. Ensure the study aligns with your PPM’s tax benefit assumptions. A quality study strengthens your offering to potential investors.
For Limited Partners (LPs)
Ask your sponsor whether they’re commissioning a cost segregation study. The accelerated depreciation flows to you on your K-1. Your ability to use the losses depends on your personal tax situation — REPS, other passive income, and overall tax position all matter.
Look-Back Studies: Capture Missed Depreciation on Properties You Already Own
If you purchased an apartment building years ago and never had a cost segregation study done, you can still capture the missed depreciation. File Form 3115 (Change in Accounting Method) with your current-year tax return. The cumulative catch-up depreciation — everything you should have taken in prior years under proper classification — hits your return as a single-year §481(a) adjustment.
No amended returns needed. The Form 3115 process applies the reclassification to your current-year return. You don’t go back and amend prior years. The entire cumulative benefit lands in one year. For a property held for 5+ years, the catch-up adjustment can be enormous — sometimes larger than a current-year study because you’re capturing multiple years of missed accelerated depreciation at once.
The OBBBA Contract Date Trap
The OBBBA requires both the binding contract date and the placed-in-service date to fall after January 19, 2025 for 100% bonus depreciation. This catches multifamily investors who signed purchase agreements before January 20, 2025 but didn’t close until after. Those properties receive only 40% bonus — not 100%.
Check your dates carefully: On a $5M apartment building with $1M in bonus-eligible components, the difference between 100% and 40% bonus depreciation is $600,000 in first-year deductions. At a 35% tax rate, that’s $210,000 in cash. If your purchase agreement was signed before January 20, 2025, ask your tax advisor whether the agreement constitutes a “binding contract” under the OBBBA rules. Some contracts may include contingencies that prevent them from qualifying as binding — which could work in your favor.
Depreciation Recapture and Exit Planning
Accelerated depreciation creates recapture exposure when you sell. Section 1245 property (5/7-year assets) faces recapture at ordinary income rates. Section 1250 property (15-year and longer) faces recapture at up to 25%. This doesn’t mean you shouldn’t accelerate — the time value of money nearly always favors taking deductions now. But you should plan for it.
1031 Exchange
Roll proceeds into a like-kind replacement property. All depreciation recapture defers indefinitely. This is the most common exit strategy for multifamily investors using cost segregation. You can 1031 from one apartment building into another — or into any other qualifying real property.
Hold and Harvest
Hold the property long-term and use cash flow for reinvestment. At death, heirs receive a stepped-up basis — eliminating all accumulated depreciation recapture. This is the ultimate tax-efficient exit for generational wealth building.
Own Apartment Buildings? Let’s Run Your Numbers.
We’ll provide a free feasibility analysis on any multifamily property — new acquisition, existing hold, or value-add renovation. You’ll see the projected reclassification, first-year tax savings, and passive activity impact before any engagement begins.
Frequently Asked Questions
What’s the minimum property value for a cost segregation study to make sense?
For multifamily properties, studies generally make economic sense at $500,000+ in depreciable basis. Smaller properties (duplexes, triplexes) may benefit from lower-cost “desktop” studies rather than full engineering studies. The feasibility analysis — which we provide free — tells you whether the projected savings justify the study cost for your specific property.
Can I do a cost segregation study on a property I’ve owned for 10 years?
Yes. A look-back study captures all missed accelerated depreciation through a Form 3115 filing on your current-year return. No amended returns are required. The catch-up adjustment often produces a larger first-year benefit than a study done at acquisition because you’re capturing multiple years of missed depreciation at once. Read our step-by-step cost segregation guide for details on the look-back process.
Do I need REPS to benefit from cost segregation?
No. REPS lets you use rental losses against active income — but cost segregation still provides value without REPS. Accelerated depreciation offsets your rental income (reducing taxes on that income), offsets other passive income if you have it, and creates suspended losses that release when you sell or exchange the property. If you have other passive-income investments, cost segregation can shelter that income immediately.
Does cost segregation work for value-add renovations?
Absolutely. If you renovate units, upgrade amenities, or improve common areas, those improvement costs have their own depreciable basis. A cost segregation study on the renovation identifies which components qualify for accelerated depreciation. For value-add investors who spend $20,000+ per unit on renovations across 50+ units, the reclassifiable basis on renovations alone can be substantial.
How does this interact with the Section 179 deduction?
Section 179 and bonus depreciation are both available for apartment buildings. Section 179 covers certain improvements (roofs, HVAC, fire protection, security systems) that may not qualify for bonus in all scenarios. It’s also more widely recognized by states that don’t conform to federal bonus depreciation. We evaluate both provisions as part of every study to maximize savings at both the federal and state levels.
What Should You Do Next?
If you own or are acquiring multifamily property — whether it’s a 10-unit building or a 500-unit complex — a cost segregation study is one of the highest-ROI tax strategies available. The OBBBA’s permanent 100% bonus depreciation makes the math even more compelling than before.
The first step is a free feasibility analysis. We’ll look at your property type, basis, acquisition date, tax situation, and passive activity status. Then we’ll give you a projected savings range — and an honest answer about whether the study makes sense for your situation.
Schedule a free consultation and we’ll run the numbers. We work with multifamily investors, syndicators, and property owners across California and nationwide.
Read our step-by-step cost segregation guide →
Cost segregation vs. bonus depreciation vs. Section 179 →
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Martin Gamez
Founder, Tax Formulations
Martin is a tax credit specialist with over 25 years of experience in cost segregation, R&D tax credits, and business tax incentives. His background includes tenure at Big Four and Top 10 accounting firms, with deep experience in accelerated depreciation strategies for multifamily, commercial, and mixed-use properties. Read full bio →