Cost Segregation for Mobile Home Parks: A Real Example with Numbers

Cost segregation is one of those concepts that park owners hear about frequently but rarely see explained in concrete terms. What does a cost segregation study actually identify on a mobile home park? How does it change the depreciation timeline? And what does the before-and-after really look like?

This post walks through a hypothetical 75-lot mobile home park acquisition and shows, using illustrative examples, what a cost segregation study produces — how assets get classified, how the depreciation timeline shifts, and how bonus depreciation interacts with the results. All numbers in this post are clearly labeled as hypothetical and illustrative. Actual results from any real study depend entirely on the specific property’s characteristics, acquisition cost, improvement composition, and the acquiring owner’s tax situation.

What Cost Segregation Actually Does

When you buy a mobile home park, the purchase price is a single number on the closing statement. That single number must be allocated among multiple asset classes — land, 5-year personal property, 15-year land improvements, and real property — because each class depreciates on a different IRS schedule.

Without a cost segregation study, that allocation is either guessed by your CPA, defaulted to a conservative real-property treatment, or done using broad industry approximations. None of these approaches is as accurate or as defensible as the engineering-based analysis a cost segregation study provides.

A cost segregation study brings in a qualified engineering firm that physically analyzes the property, reviews construction documents and as-built records, and categorizes each component using IRS-prescribed criteria. The result is a detailed asset list with a documented basis allocated to each line item — the same information your depreciation schedule needs to generate correct annual deductions.

The Hypothetical: A 75-Lot MHP Acquisition

For this illustration, assume a park owner acquires a 75-lot mobile home park. The purchase price is allocated after the study. The park has a mix of park-owned homes and tenant-owned home lots, along with roads, utility infrastructure, and a small office building.

Without a cost segregation study, a typical general-practice CPA might set up the depreciation as follows — a simplified, two-class structure that understates the fast-depreciation components:

This approach treats every depreciable asset — the homes, the roads, the water lines, the fencing — as 27.5-year residential real property. That is the error that costs park owners money.

What the Cost Segregation Study Identifies

With a proper cost segregation study applied to the same hypothetical acquisition, the engineering analysis breaks the depreciable basis into its correct components. The specific percentages for any real property will vary — but to illustrate the structural shift, a study on this type of property might reveal an allocation similar to the following:

The key shift: in the no-cost-segregation scenario, 80% of the depreciable basis was on a 27.5-year straight-line schedule. After the study, roughly 55% of the purchase price (the 5-year and 15-year classes combined) is on accelerated schedules and eligible for bonus depreciation. That is a structural transformation of the depreciation timeline — not a marginal improvement.

The Depreciation Timeline: Before and After

The difference in depreciation timing between the two approaches is substantial in the early years. In the no-cost-segregation scenario, every depreciable dollar is spread ratably across 27.5 years. In the cost segregation scenario, a significant portion of the depreciable basis is recovered in years 1 through 6 (5-year assets) or years 1 through 16 (15-year assets), with larger deductions front-loaded in the early years through the declining balance methods.

When bonus depreciation applies to the 5-year and 15-year assets, the acceleration is even more pronounced. A significant portion of those classes can be deducted in year one, leaving only the residual basis (reduced by the bonus taken) to depreciate under the regular MACRS schedule over the remaining recovery period.

The long-term total depreciation is identical in both scenarios — both eventually recover the full depreciable basis. What changes is when those deductions occur. Cost segregation moves them earlier. Earlier deductions are worth more due to the time value of money, and they also provide more flexibility to manage taxable income in the years when the park is generating strong NOI.

How Bonus Depreciation Amplifies the Cost Segregation Result

Cost segregation identifies which assets belong in the 5-year and 15-year bonus-eligible classes. Bonus depreciation is what allows you to deduct a large portion of those assets’ cost in year one rather than spreading them across the recovery period.

The two work in sequence: cost segregation first moves assets into bonus-eligible classes by documenting their correct classification. Then bonus depreciation accelerates the deduction for those correctly classified assets. Without cost segregation, most MHP assets remain in the 27.5-year class and are ineligible for bonus depreciation. The study creates the eligibility; the election captures it.

For acquisitions where a large share of the purchase price is allocated to 5-year and 15-year assets, and where the applicable bonus rate is significant, the combined effect can produce a first-year depreciation deduction that substantially exceeds the typical annual MACRS deduction. Park owners with strong taxable income from the park — or from other passive income sources — can use these deductions to significantly reduce their tax liability in the acquisition year.

What Qualifies for a Cost Segregation Study?

Not every MHP acquisition warrants a formal engineering cost segregation study. The study itself has a cost — typically a professional fee paid to the engineering firm. For the study to be economically justified, the additional depreciation generated by the study must meaningfully exceed the cost of the study.

General guidance: acquisitions with a significant improvement component and a total purchase price above a threshold where the acceleration benefit is meaningful tend to be good candidates. Parks with substantial POH inventories or significant infrastructure are often strong candidates because those asset classes produce the largest reclassification from 27.5-year to 5-year and 15-year property.

Parks with very minimal improvement content — predominantly land value with few improvements — may produce a smaller benefit from formal cost segregation. The cost-benefit analysis is specific to each acquisition and should be run by your MHP CPA before the study is commissioned.

For a detailed decision framework — when a study makes sense, what it costs, and what questions to ask — see our dedicated post on what a cost segregation study is and whether you need one.

The Lookback Study: Applying Cost Segregation to Prior Acquisitions

If you own a park that was acquired without a cost segregation study and has been depreciating as undifferentiated real property, you are not out of options. A lookback cost segregation study analyzes the property as it was at the time of original acquisition and identifies the assets that should have been classified in the 5-year and 15-year classes from day one.

The cumulative missed depreciation — the difference between what was taken and what should have been taken under correct classification — is captured through a Section 481(a) adjustment on a Form 3115 filing. This adjustment typically appears as a lump-sum deduction in the year the accounting method change is filed.

There is no IRS-imposed deadline on when this correction must be made. Parks acquired several years ago with consistent misclassification can still benefit from a lookback study today. The earlier the correction is made, the sooner the proper depreciation schedule is in place going forward. Learn more about how this correction fits into an overall MHP accounting strategy and how it connects to your depreciation approach for the full park.

Frequently Asked Questions

For authoritative IRS guidance on cost recovery and asset classification, see IRS Publication 946: How to Depreciate Property.

This content is for educational purposes only and does not constitute tax or legal advice. The MHP Accountant recommends consulting a qualified CPA for advice specific to your situation.