A property placed in service on December 15 generates the same first-year bonus depreciation as one placed in service on January 15. The only difference is which tax year the deduction falls in. A December placed-in-service date captures it on this year's return instead of next year's.
Most investors assume a late-year purchase means partial-year deductions. For standard depreciation, that is partly true. For bonus depreciation, the largest first-year component of a cost segregation benefit, it is not true at all.
Strategic timing of acquisitions around year-end can accelerate your tax benefits by a full tax year. This article covers the placed-in-service rules, how bonus depreciation works regardless of purchase month, the advantages of December closings, who can actually use the deduction, and the timing mistakes that cost investors money.
The Placed-in-Service Rule: Why Purchase Month Matters Less Than You Think
Depreciation does not begin when you close. It begins when the property is placed in service, meaning it is ready and available for its intended use. The IRS treats a rental as placed in service once it is ready and available for rent and held out for rent (IRS Publication 527).
You do not need a tenant or a signed lease, and minor punch-list items do not delay the date, but you do need to show the property was being offered before December 31 (a listing, an advertisement, or engagement of a property manager). Rentable condition alone, with no offering activity, is the fact pattern that loses on audit.
This matters because of how bonus depreciation works.
Under the One Big Beautiful Bill Act, 100% bonus depreciation is permanent for qualified property acquired and placed in service after January 19, 2025 (IRS). Reclassified components from a cost segregation study are deducted in full in the year the property is placed in service. This deduction is not prorated by month. Whether you place the property in service on January 2 or December 30, the bonus depreciation deduction is identical.
One caveat: property under a written binding contract before January 20, 2025 stays on the old phase-down schedule, so confirm your acquisition date with your CPA.
Standard depreciation on the remaining basis uses the mid-month convention (IRS Publication 946). A December placed-in-service date gives you only half a month of standard depreciation that year. That standard portion is a small fraction of the total first-year benefit when cost segregation is involved.
Here is the math for a $1 million residential rental placed in service on December 1. The figures use a 15% land allocation and a 33% reclassification, both of which vary by property and location:
- Depreciable basis (after 15% land): $850,000
- Cost segregation reclassifies 33% into 5- and 15-year property: $280,500
- Bonus depreciation (full year, not prorated): $280,500
- Standard depreciation on the remaining $569,500 (half-month): ~$865
- Total first-year deduction: ~$281,365
At a 37% marginal rate, that deduction is worth about $104,000, but only if you can use it against your income (see below).
Month-by-Month Comparison: When Timing Matters Most
The best way to understand December's advantage is to compare it against other purchase months. The table below uses the same $1 million property, an $850,000 depreciable basis, and $280,500 in reclassified components:
The bonus depreciation column is identical across all three months. Only the standard depreciation on the remaining basis changes, varying by about $19,000 between January and December. That $19,000 difference is small next to the $280,500 in bonus depreciation, which does not change at all.
Should I wait until January to close?
Almost never. Waiting until January delays the entire $280,500 bonus depreciation deduction by a full year. You would trade $280,500 in current-year deductions for roughly $19,000 in extra standard depreciation next year. Closing in December is almost always the stronger move.
The real question is not which month you close. It is which tax year you want the deduction in. If this year's income is unusually high from a bonus, a capital gain, or a business sale, closing before December 31 captures the deduction when it delivers the most value.
Can You Actually Use the Deduction?
A large first-year deduction only helps if you can apply it against your income. Rental real estate losses are generally passive, and passive losses can only offset passive income unless you meet an exception (IRS Publication 925). Three common paths let investors use these losses against other income:
- Real Estate Professional Status. Investors who meet the 750-hour and material participation tests can deduct rental losses against active income. See our guide to Real Estate Professional Status.
- The short-term rental exception. Materially participating in an STR with an average guest stay of seven days or less can make the activity non-passive. See how the short-term rental loophole works.
- The $25,000 special allowance. Active participants with modified adjusted gross income under $100,000 may deduct up to $25,000 of rental losses, phasing out completely at $150,000.
If none of these apply, your deduction is not lost. It carries forward as a suspended passive loss until you have passive income or sell the property. Even when one of the three exceptions above applies and the losses are non-passive, the §461(l) excess business loss limitation caps how much can offset wages and portfolio income in one year (roughly $256,000 single / $512,000 married filing jointly for 2026); the excess carries forward as an NOL. Model your specific situation with your CPA before assuming a dollar figure of savings.
Year-End Strategies That Maximize Your Deductions
December closings require coordination. Four strategies help you capture every available deduction.
Strategy 1: Close and Place in Service Before December 31
This is the most important step. A December closing captures the deduction in the current tax year, while a January closing delays it by twelve months. If you are negotiating a deal in Q4, push for a year-end close.
The property must be placed in service before year-end, not just closed. For a turnkey rental, closing and placed-in-service usually happen together. For a property that needs work, confirm it will be in rentable condition before December 31.
Strategy 2: Order Your Cost Segregation Study Early
Do not wait until closing to contact a cost segregation firm. Many firms begin preliminary analysis before closing, using listing photos, floor plans, and property details. The final cost segregation report can be completed within weeks of closing, well before your tax return is due.
Ordering early ensures your CPA has the study results when preparing your return. Last-minute orders risk delays that push filing into extension territory.
Strategy 3: Combine With a Look-Back Study
You can also pair a new acquisition with a look-back study on property you already own. A look-back study uses Form 3115 to claim missed accelerated depreciation as a single catch-up adjustment on your current-year return. It is not tied to year-end. Form 3115 can be filed with any timely return, and there is no statute of limitations on catching up missed depreciation.
Pairing a new acquisition study with look-back studies on your existing portfolio lets the combined deductions land on a single return.
Strategy 4: Coordinate With Your CPA on Estimated Taxes
Large December deductions can reduce your Q4 estimated tax payment or generate a refund. Tell your CPA before year-end so they can adjust your estimates. Some investors overpay all year. At filing, they learn a December cost segregation study could have saved them thousands in avoidable payments.
Here is what this looks like in practice. An investor closes on a $1.5 million multifamily property on December 20 and places it in service the same week. The study was ordered before closing and delivered in late January. It reclassifies $420,000 into accelerated categories, roughly 28% of the purchase price. Because the deal closed 11 days before the deadline, the investor claims $420,000 in additional deductions on the current-year return. At a 37% rate, and assuming the loss is usable, that is worth about $155,400.
Before You Close: Three Things to Weigh
Accelerating depreciation is powerful, but factor in three points before you plan around it.
- Depreciation recapture. Accelerated deductions increase the depreciation you may have to recapture when you sell. Understand how recapture affects your eventual exit.
- State conformity. Not every state follows federal bonus depreciation rules, so your state deduction may differ from your federal one. Confirm your state's treatment with your CPA.
- The mid-quarter convention. If more than 40% of your depreciable personal property is placed in service in the fourth quarter, the mid-quarter convention applies to that property. With 100% bonus depreciation expensing those components in year one, it rarely changes the result, but your preparer should confirm it.
Common Timing Mistakes That Cost Investors Money
These errors repeat every year-end, and each one is preventable.
- Delaying a close to January "for a fresh start." This defers the entire bonus depreciation deduction by a full year for no strategic reason.
- Failing to have the property ready and available before year-end. If major renovations are underway and the property cannot be occupied, the placed-in-service date may fall into the next year. Plan renovations accordingly or confirm the property is in rentable condition.
- Ordering the cost segregation study too late. Firms get busy in Q4, so starting in November gives you the best chance of results before filing.
- Assuming partial-year ownership disqualifies you from full bonus depreciation. It does not. Bonus depreciation is a full-year deduction regardless of the placed-in-service month.
- Assuming the deduction automatically offsets any income. It may be a suspended passive loss unless you qualify under the rules above.
- Forgetting to coordinate with your CPA on estimated payments.
What if my property isn't rented by December 31?
It does not need to be rented. The IRS standard is ready and available for its intended use, and held out for rent. If the property is in rentable condition (utilities on, appliances installed, no major construction ongoing) and you can show it was being offered before December 31 (a listing, an advertisement, or engagement of a property manager), it qualifies as placed in service. Minor punch-list items do not delay the date, and you do not need a signed lease or a tenant in place. What you do need is evidence of offering activity: if a December placed-in-service date is knocked out on audit because the property was never listed or marketed, the full bonus deduction slides to the following year.
Close the Year Strong
Key takeaways:
- Bonus depreciation is not prorated. A December placed-in-service date earns the same deduction as a January one.
- The placed-in-service date matters more than the closing date. The property must be ready and available for rental use.
- A December close captures the deduction a full tax year earlier. The smaller standard depreciation (about $19,000 on our $1M example) is minor next to the bonus deduction.
- Confirm you can use the deduction. Passive loss rules may suspend it unless you qualify as a real estate professional, use the STR exception, or meet the $25,000 allowance.
- Order your study early and coordinate with your CPA on estimated taxes. A $280,500 first-year deduction can cut a top-bracket investor's tax by roughly $104,000 when the loss is usable.
December is not too late. For many investors it is the best month to close, capturing a full year of bonus depreciation benefits with just days of ownership.
Ready to model your year-end purchase? Get a free proposal and see your specific first-year numbers before the deadline.
