Solo 401(k) Loan Rules: Can You Borrow From Your Solo 401(k)?

Yes — a Solo 401(k) can allow loans, but only if the plan document specifically authorizes them. The rules come from IRC §72(p): you can borrow the lesser of $50,000 or 50% of your vested balance, repay over five years with interest, and never miss a payment or the IRS treats the outstanding balance as a taxable distribution. Here's what every business owner needs to know before borrowing from their own retirement plan.

How Solo 401(k) loans work

A Solo 401(k) loan is not a withdrawal. You borrow from your own retirement account balance, make repayments (with interest) back into the plan, and — if you follow the rules — owe no taxes on the borrowed amount. The catch: if you miss even one payment, the IRS treats the outstanding loan balance as a "deemed distribution," triggering income tax plus a 10% early withdrawal penalty if you're under 59½.

Unlike a bank loan, there is no credit check, no underwriting, and no lender approval — but there is a strict set of IRS rules you must follow as both the plan participant and the plan administrator.

Loan limits under IRC §72(p)

The maximum loan amount is the lesser of:

1. $50,000, reduced by the highest outstanding loan balance in the prior 12 months¹
2. 50% of your vested account balance

The $50,000 limit is a statutory ceiling in IRC §72(p) and is not indexed for inflation. It has been $50,000 since 1982.

Repayment rules

The IRS requires that a 401(k) loan be repaid in level amortization payments of equal amounts made at least quarterly, within 5 years — except for a primary residence purchase.¹

Non-residence loans (5-year maximum)

For any loan purpose other than buying your primary residence, the plan must require repayment in full within 5 years. Monthly payment on a $50,000 loan at a 9.5% interest rate over 5 years (60 months) is approximately $1,042/month. You repay this to your own plan account.

Primary residence exception

Plans may allow a longer repayment period for loans used to acquire the participant's principal residence — up to whatever period the plan document specifies (often up to 25-30 years, mimicking a mortgage). The plan document must explicitly authorize this exception and you must use the proceeds specifically to purchase a primary home (not a vacation home or rental property).

Interest rate

IRC §72(p) requires a "reasonable rate of interest" — the statute doesn't specify a formula, but the IRS's longstanding guidance and plan practice is to use the prime rate plus 1 to 2 percentage points at the time the loan is made.²

A key point: you are paying interest to yourself. The interest you pay goes back into your own retirement account as a plan contribution of sorts. From a pure return standpoint, the loan interest isn't "lost" — but there is a tax drag, discussed below.

The biggest risk: deemed distribution

If you miss a required payment (fail to make level amortization payments at least quarterly), the IRS treats the entire outstanding loan balance as a taxable distribution on the last day of the grace period.¹

Consequences of a deemed distribution:

• The outstanding balance is included in your ordinary income for that year
• If you are under 59½, you owe a 10% early withdrawal penalty on top of income tax
• The deemed distribution is reported on Form 1099-R
• A deemed distribution is not eligible for rollover — you cannot fix it by putting the money back into the plan

Unlike a bank, your Solo 401(k) has no automatic payroll deduction mechanism enforcing payments. As the plan administrator, you must set up your own repayment schedule and track it. An IRS-approved form loan agreement with scheduled payment dates is essential — this creates a paper trail showing the plan's required amortization schedule was established at origination.

The plan document requirement

Not every Solo 401(k) allows loans. The plan document must specifically authorize participant loans — this is an optional feature that plan sponsors (you, as the employer) choose to include or exclude at plan adoption. Many low-cost Solo 401(k) templates do not include loan provisions to keep the document simple.

Before assuming you can borrow from your Solo 401(k), check your actual plan document. Look for a section titled "Loans" or "Participant Loans" with language authorizing them and specifying maximum amounts and repayment terms. If the document is silent on loans, you cannot offer them without amending the plan.

If your plan doesn't currently allow loans and you want to add that feature, you'll need a plan amendment. Amending a Solo 401(k) plan document is typically inexpensive ($100–300) if you use a provider like Fidelity, Vanguard, Schwab, or a third-party administrator — but it must be done before the loan is made, not after.

Plan termination and the QPLO rule

What happens if you close your business, terminate the Solo 401(k) plan, or roll it over to an IRA while you have an outstanding loan?

When a plan terminates with an outstanding loan, the loan balance becomes a Qualified Plan Loan Offset (QPLO) — the plan "distributes" the loan balance as an offset against your account. This triggers the same tax and penalty consequences as a deemed distribution unless you take action.

The relief: Under IRC §402(c)(3)(C) (enacted in the Tax Cuts and Jobs Act of 2017), a QPLO arising from plan termination or severance from employment can be rolled over to another eligible retirement plan by your federal income tax filing deadline, including extensions, for the year in which the QPLO occurred — not the usual 60-day rollover window.³

Practical example: your Solo 401(k) terminates in March 2026 with a $35,000 outstanding loan. You have until October 15, 2027 (with extensions) to deposit $35,000 into a rollover IRA or new 401(k) plan to avoid the tax and penalty. This gives meaningful runway — but it requires having $35,000 in cash available to fund the rollover.

The double-taxation problem

Financial planners often call 401(k) loans "double-taxed." Here's what that means in practice:

1. Your original pre-tax contributions went into the plan before tax — you deducted them.
2. You take a loan and repay it with after-tax dollars (your net paycheck or after-tax business income).
3. When you eventually withdraw the loan repayments in retirement, you pay income tax again on those same dollars.

The interest you pay yourself also creates this double-tax effect. However, the magnitude is often smaller than it seems: if you're in the 32% bracket now and the 22% bracket in retirement, the "double tax" on the interest is the difference in those rates, not the full interest amount. The practical cost is often $2,000–$5,000 in additional tax on a $50,000 loan over 5 years — real but not catastrophic if the loan is genuinely the best available option.

The larger issue for a business owner is often opportunity cost: while the money is borrowed, it's out of the market. If markets return 8% annually and your loan rate is 9.5%, the loan is roughly cash-flow-neutral from a growth standpoint, but you've given up the tax-free compounding on the borrowed amount.

Solo 401(k) loan vs. alternatives

A Solo 401(k) loan is rarely the cheapest option — but it may be the fastest or most accessible when other doors are closed. Compare before borrowing:

A Solo 401(k) loan makes the most sense when: (1) you need money quickly and can't wait for bank underwriting; (2) you have limited equity or credit history for conventional financing; (3) the amount needed is under $50,000; or (4) you're confident you can repay on schedule within 5 years without disrupting business cash flow.

It makes the least sense when the balance is low (borrowing half of a $30,000 account for $15,000 dramatically reduces your compounding base), or when you're within 3-5 years of needing the money in retirement (not enough time to recover from the lost growth).

Common mistakes

• Borrowing from a plan that doesn't allow loans. This creates a "prohibited transaction" under IRC §4975 — a 15% excise tax on the amount involved, plus potential plan disqualification. Check the plan document first.
• Missing a payment. Even one missed quarterly payment triggers a deemed distribution. Set up automatic bank transfers on the repayment schedule and monitor them.
• Believing the plan termination exception is a rollover. The QPLO rollover requires you to deposit cash into a new plan within the filing deadline. You cannot "re-contribute" the outstanding loan balance — you need new dollars equal to the loan balance.
• Taking a loan shortly before plan termination. If you take a $50,000 loan and terminate the plan 6 months later, you owe $50,000 in new cash to avoid the tax and penalty. Plan terminations should be coordinated with outstanding loan balances.
• Not documenting the loan agreement. The IRS requires a legally binding loan agreement specifying the amount, repayment schedule, and interest rate. A verbal arrangement between you (as participant) and yourself (as plan administrator) doesn't satisfy the documentation requirement.

Sources

1. IRS — Retirement Plans FAQs Regarding Loans. Confirms §72(p) loan limits ($50,000 or 50% of vested balance), 5-year repayment requirement, quarterly level amortization, deemed distribution rules, and primary residence exception. Values reflect current statutory provisions; the $50,000 limit has been unchanged since TEFRA 1982.
2. U.S. Department of Labor — Plan Loans. DOL guidance confirming that plan loans must bear a reasonable rate of interest, be adequately secured, and follow plan terms consistent with ERISA requirements. Market practice of prime + 1–2% satisfies the reasonable rate standard per DOL Field Assistance Bulletin 2003-3.
3. IRS Notice 2017-72 — Extension of Rollover Period for Plan Loan Offset Amounts. Implements IRC §402(c)(3)(C) as enacted by the Tax Cuts and Jobs Act of 2017 (TCJA). Qualified Plan Loan Offset (QPLO) amounts arising from plan termination or severance from employment may be rolled over to an eligible retirement plan by the federal income tax filing deadline (including extensions) for the year the offset occurs.
4. IRS Publication 560 — Retirement Plans for Small Business. Authoritative IRS guidance on Solo 401(k) plan requirements, including the requirement that loans be authorized by the plan document and that the plan document specify loan terms consistent with §72(p). Values verified as of June 2026.

IRC §72(p) loan limits and repayment rules are statutory and have not changed since TEFRA 1982. QPLO rollover extension per TCJA (2017). Values verified as of June 2026.