Self-Directed IRAs and Solo 401(k)s: Real Estate, Crypto, and Alternative Investments in Retirement Accounts

Most retirement accounts are limited to publicly-traded securities — stocks, bonds, mutual funds, and ETFs. Self-directed retirement accounts open the door to a dramatically broader investment universe: real estate, private equity, cryptocurrency, precious metals, private lending, tax liens, and virtually any asset not specifically prohibited by IRS rules. For sophisticated investors with strong alternative investment opportunities, self-directed accounts can dramatically expand both diversification and after-tax returns. But the rules are technical, and prohibited transaction violations can disqualify the entire retirement account — with catastrophic tax consequences.

Self-Directed IRAs vs Self-Directed Solo 401(k)s

Two primary vehicles support alternative investments in retirement accounts:

Self-Directed IRA (SDIRA)

An IRA held with a custodian that permits non-traditional investments. The custodian (firms like Equity Trust, Quest Trust, IRA Financial, NuView Trust) holds title to the assets on behalf of the IRA. Every transaction must be processed through the custodian — purchase contracts, payments, rental income, expenses.

Self-Directed Solo 401(k) ("Checkbook Control")

A Solo 401(k) plan with the assets held in a trust account that the plan trustee (typically the business owner) can directly access — the so-called "checkbook control" structure. Provides faster transaction execution and lower ongoing custodian fees, but requires more compliance discipline from the trustee.

The Solo 401(k) structure is generally preferred for active alternative investors because of:

• Higher 2026 annual limits: a $72,000 defined-contribution annual-additions limit before applicable catch-up contributions, compared with a $7,500 IRA contribution limit before the age-50 catch-up, subject to compensation and other rules.

• Direct trustee control eliminating per-transaction custodian fees.

• Participant loans when the plan document permits them, generally limited to the lesser of 50% of the vested balance or $50,000 and subject to repayment and prior-high-balance rules.

• Cleaner UBIT treatment for leveraged real estate (more on this below).

Allowable Alternative Investments

Self-directed retirement accounts can invest in:

• Real estate — residential, commercial, land, foreign property.

• Private mortgages and loans to unrelated parties.

• Tax liens and tax deeds.

• Private business equity (LLC interests, partnership interests, private company stock).

• Cryptocurrency (Bitcoin, Ethereum, and other digital assets).

• Precious metals (gold, silver, platinum, palladium meeting purity requirements).

• Royalty interests in oil, gas, or intellectual property.

• Private lending through platforms or direct loans.

• Foreign assets including foreign real estate and securities.

Prohibited Investments

A short list of investments that retirement accounts cannot hold:

• Collectibles — art, antiques, gems, stamps, alcoholic beverages, most coins (limited exception for U.S. Eagle and certain bullion).

• Life insurance contracts.

• S-corporation stock (IRAs cannot be S-corp shareholders).

• Certain partnership interests in family or controlled partnerships (prohibited transaction issues).

The Prohibited Transaction Rules

The most dangerous aspect of self-directed accounts is the prohibited transaction rules under §4975. A prohibited transaction with a "disqualified person" can result in the IRA being deemed distributed in its entirety as of January 1 of the year of the violation — triggering income tax on the full balance plus 10% early withdrawal penalty (if under 59½).

Disqualified Persons

• The IRA owner.

• The IRA owner's spouse, ancestors, lineal descendants, and their spouses.

• Fiduciaries to the IRA.

• Service providers to the IRA.

• Any entity owned 50%+ by disqualified persons.

Prohibited Transactions

• Selling, exchanging, or leasing property between the IRA and a disqualified person.

• Lending money or extending credit between the IRA and a disqualified person.

• Furnishing goods, services, or facilities between the IRA and a disqualified person.

• Transferring IRA assets to a disqualified person.

• Using the IRA for the benefit of a disqualified person.

Practical examples:

• Prohibited: Living in or vacationing at a property owned by your IRA.

• Prohibited: Renting your IRA-owned property to your son or daughter.

• Prohibited: Selling your personal property to your IRA.

• Prohibited: Performing repairs or improvements yourself on your IRA-owned property.

• Prohibited: Receiving compensation from your IRA-owned business.

• Prohibited: Personally guaranteeing a loan made to your IRA.

Unrelated Business Income Tax (UBIT)

Income earned by a tax-exempt entity (including retirement accounts) from operating a business unrelated to the entity's exempt purpose can be subject to Unrelated Business Income Tax (UBIT) at trust tax rates; for 2026, the 37% estate-and-trust bracket begins above $16,000 of taxable income.

UBIT applies when the IRA:

• Operates an active business directly.

• Holds an interest in a partnership or LLC that operates an active business.

• Earns income from debt-financed property (UDFI — discussed below).

UBIT does NOT apply to:

• Passive rental income from real estate (with limited exceptions).

• Dividends, interest, and capital gains from securities.

• Royalties.

Unrelated Debt-Financed Income (UDFI)

When an IRA acquires real estate or other property using debt financing, a portion of the income from that property becomes subject to UDFI taxation. The portion is calculated based on the average debt-to-basis ratio over the year.

For a property purchased with 50% financing:

• 50% of rental income is subject to UDFI (taxed at trust rates).

• 50% of capital gains on sale subject to UDFI.

UDFI represents one of the major drawbacks of leveraged real estate in IRAs.

The Solo 401(k) UDFI Exception

A qualified retirement trust, including a Solo 401(k), may use the statutory real-property acquisition-debt exception to avoid UDFI, but only when the property, debt, lease, seller, and related-party conditions are satisfied. It is not an unconditional exclusion for every leveraged 401(k) real estate investment.

For active real estate investors planning to use leverage in a retirement account, compare the potential 401(k) exception with the plan document, prohibited-transaction rules, financing terms, and UBIT reporting before choosing the structure.

Cryptocurrency in Self-Directed Accounts

Cryptocurrency is a permitted self-directed IRA investment but requires specific custodian arrangements:

• Crypto-friendly SDIRA custodians (Bitcoin IRA, BitIRA, iTrustCapital, Alto, Kingdom Trust).

• Solo 401(k) plans with appropriate cryptocurrency custody arrangements.

• "Crypto-only" IRAs with specialized providers.

For long-term Bitcoin or Ethereum investors expecting significant appreciation, holding the position in a Roth IRA or Roth Solo 401(k) provides tax-free growth — potentially extraordinary value over multi-decade horizons.

Real Estate in Self-Directed Accounts

Real estate is the most common alternative IRA investment. Considerations:

• All purchase costs must come from IRA funds — including down payment, closing costs, repairs, improvements.

• All operating expenses (property taxes, insurance, utilities, repairs, management fees) must be paid from IRA funds.

• All income (rent, sale proceeds) must flow back to the IRA.

• The IRA owner cannot personally provide services (cannot personally make repairs, manage tenants, or provide other "sweat equity").

• Properties cannot be used personally by the IRA owner or family members (even one night of personal use is a prohibited transaction).

For real estate investors with strong deal flow but limited personal capital, SDIRAs and Solo 401(k)s open up retirement account capital for real estate investment.

Required Minimum Distributions Challenges

Traditional self-directed IRAs and 401(k)s face the same RMD rules as conventional accounts. The applicable starting age generally is 73 for individuals born from 1951 through 1959 and 75 for those born in 1960 or later; older cohorts may have earlier applicable ages. For accounts holding illiquid assets like real estate:

• RMDs may be distributed in cash or in kind, but illiquid property can make valuation, transfer, withholding, and partial-distribution mechanics difficult.

• If the account does not have sufficient liquidity, the owner should plan early rather than assume an asset can be sold or transferred by the deadline.

• An in-kind distribution is generally included in income at the property's fair market value, subject to basis and other distribution rules.

Roth IRAs are NOT subject to lifetime RMDs, eliminating this challenge for Roth-converted balances.

Custodian Selection

For SDIRAs, custodian selection matters significantly. Compare:

• Setup fees ($50-$500).

• Annual fees ($300-$3,000+ depending on assets and complexity).

• Per-transaction fees ($25-$250 per asset purchase or sale).

• Asset class capabilities (some custodians don't handle crypto, some don't handle private equity, etc.).

• Customer service quality and processing speed.

• Compliance support for complex transactions.

Common Mistakes

• Engaging in prohibited transactions (catastrophic — disqualifies the entire account).

• Using IRA assets for personal benefit even briefly.

• Failing to coordinate UBIT/UDFI obligations.

• Selecting an SDIRA custodian without comparing costs and capabilities.

• Choosing an IRA or Solo 401(k) for leveraged real estate without testing UDFI, the conditional qualified-organization real-property exception, prohibited transactions, plan terms, and financing facts.

• Trying to provide personal services to IRA-owned property.

• Lacking liquidity to meet future RMDs on illiquid IRA holdings.

Bottom Line

Self-directed retirement accounts are powerful tools for sophisticated investors with strong alternative investment opportunities — but the prohibited transaction rules are unforgiving. For real estate investors, private business owners, and crypto investors with long time horizons, the ability to hold these assets in tax-advantaged retirement accounts can dramatically improve after-tax returns. Working with a CPA experienced in self-directed retirement accounts is essential to navigate the prohibited transaction landscape safely.