Self-Directed IRA Investing in Mobile Home Parks: Tax Rules Explained

Using a self-directed IRA to invest in a mobile home park sounds appealing on paper: tax-deferred or tax-free growth, passive income accumulating inside a retirement account, and exposure to an asset class that has historically provided stable cash flow. But the rules governing IRA investments in alternative assets — and in MHPs specifically — are complex, unforgiving, and full of traps for the uninformed investor.

This guide is written to give you an accurate, balanced picture of what self-directed IRA investing in an MHP actually involves. Not to sell you on the strategy — but to ensure you understand the rules before you proceed.

What Is a Self-Directed IRA?

A self-directed IRA (SDIRA) is a traditional or Roth IRA that allows investment in assets beyond the stocks, bonds, and mutual funds available through most brokerage custodians. SDIRAs are administered by specialized custodians who are willing to hold alternative assets such as real estate, private placements, and — yes — mobile home park interests.

The SDIRA itself isn’t a special type of account under the Internal Revenue Code. All IRAs operate under the same section of the tax code (IRC §408). The “self-directed” designation simply means the custodian allows you to direct investments into alternative asset classes that most large brokerages won’t accommodate.

Key requirement: the IRA must hold the ownership interest in the MHP — not you personally. When your SDIRA invests in an MHP, the IRA is the member of the LLC or the limited partner in the LP — not you. This distinction is critical for understanding both the tax treatment and the prohibited transaction rules.

The Prohibited Transaction Rules

The most dangerous aspect of SDIRA investing is the prohibited transaction rules under IRC §4975. A prohibited transaction disqualifies the entire IRA — not just the investment — resulting in the entire account balance being treated as a taxable distribution in the year the transaction occurs. For a large IRA, this can be a catastrophic tax event.

The core prohibition: you cannot engage in any transaction between your IRA and a “disqualified person.” Disqualified persons include you, your spouse, your lineal ascendants and descendants, entities you control (50% or more), and fiduciaries of the IRA.

For MHP investing, the most common prohibited transactions are:

• Self-dealing: You cannot perform services for the IRA-owned MHP personally — no managing the property yourself, no collecting rent, no doing maintenance work. All services must be provided by unrelated third parties paid at fair market value.
• Personal benefit: You cannot personally benefit from the IRA-owned asset. You cannot stay in a POH, use the park clubhouse, or receive any non-IRA income related to the park.
• Loans between the IRA and disqualified persons: The IRA cannot lend money to you or your family members, and you cannot personally guarantee the IRA’s debt (relevant to the UBIT discussion below).
• Sales between the IRA and disqualified persons: You cannot sell your personally owned assets to the IRA, or buy the IRA’s assets from it, at any price — fair market value does not cure a prohibited transaction.

The practical implication: if your SDIRA owns an MHP, you are completely hands-off. You must hire a third-party manager, use an unrelated attorney, and ensure every service provider is compensated by the IRA at arm’s length rates. Your role is limited to directing the investment — not operating it.

Unrelated Business Income Tax (UBIT)

One of the most significant and least understood consequences of using an SDIRA to invest in a leveraged MHP is the Unrelated Business Income Tax (UBIT). This tax exists specifically to prevent IRAs and other tax-exempt entities from generating untaxed income from commercial activities funded with debt.

Under IRC §514, when a tax-exempt entity (including an IRA) holds “debt-financed property,” the income attributable to the debt-financed portion is subject to UBIT. The applicable rate is the trust tax rate, which reaches the top marginal rate at a relatively low income threshold.

Here’s what that means for an MHP investment. If your SDIRA borrows to purchase an MHP (using non-recourse financing — the only type of debt allowed inside an IRA), a portion of the park’s net income is treated as unrelated business taxable income. The proportion equals the “acquisition indebtedness” (outstanding loan balance) as a percentage of the adjusted basis of the property.

Example: Your IRA owns an MHP with an adjusted basis of $1 million. The IRA borrowed $600,000 to acquire it, and the outstanding balance is $600,000. The “average acquisition indebtedness percentage” is 60%. If the park generates $100,000 in net income, $60,000 is subject to UBIT. At the applicable tax rate, this generates a tax bill that the IRA pays — reducing the benefit of tax-deferred or tax-free growth.

As the loan is paid down, the UBIT percentage decreases. An MHP purchased with all cash (no leverage) inside an IRA generates no UBIT from the debt-financed property rules — though other UBIT sources may exist if the park conducts active business activities.

UBIT Filing Requirements

If your SDIRA has UBIT income exceeding $1,000 for the tax year, the IRA must file Form 990-T (Exempt Organization Business Income Tax Return) and pay the tax. The custodian of the IRA typically assists with this filing, but you should confirm they have the capability before investing.

The IRA itself pays the UBIT — not you personally. The tax reduces the IRA’s balance, which in turn reduces the ultimate benefit of the tax-deferred structure.

Many SDIRA investors in leveraged real estate are surprised by UBIT because they assumed all income inside an IRA is tax-free. It’s not — UBIT applies to debt-financed income regardless of account type, including Roth IRAs.

Who Should Consider SDIRA Investing for MHP?

Based on the complexity and the UBIT exposure, SDIRA investing in an MHP is most appropriate in a limited set of circumstances:

• Large traditional IRA with no immediate withdrawal needs — the tax deferral benefit is most valuable when you have a long time horizon and won’t need distributions for many years
• All-cash (no leverage) purchase — eliminates UBIT and simplifies compliance significantly; requires a very large IRA balance for a park of any size
• Passive equity investment in an MHP fund or limited partnership — a smaller SDIRA can participate as a passive LP investor without triggering the management-related prohibited transaction issues; leverage inside the LP still generates UBIT proportionally
• Investor who has already maximized direct ownership strategies — if you’ve exhausted your direct MHP investment capacity and have a large qualified retirement account sitting in low-yield assets, SDIRA may be worth exploring

SDIRA vs. Direct MHP Ownership: A Balanced Comparison

The most powerful tax tool for MHP direct ownership — MACRS depreciation with bonus depreciation — is completely unavailable inside an IRA. IRAs don’t pay income tax on operations, so there’s no benefit from depreciation deductions. This is the fundamental tradeoff: the IRA defers or eliminates tax on income, but gives up all the depreciation benefits that make direct MHP ownership so tax-efficient.

For further context, see our guides on passive activity rules for MHP owners and estate planning for MHP owners.

For authoritative IRS guidance on prohibited transactions, see IRS.gov: Prohibited Transactions.

Disclaimer: This content is provided for general educational purposes only and does not constitute tax, legal, or financial advice. SDIRA investing involves complex prohibited transaction and UBIT rules that vary based on individual circumstances. Consult a qualified tax professional and financial advisor before making any SDIRA investment decisions. The MHP Accountant® provides tax services — not legal advice or investment advice.