A 401(k) loan vs a family loan comes down to one trade: borrow from your own retirement account and risk a tax bomb if you lose your job, or borrow from a relative and risk the relationship if something goes wrong. Neither is free money. For most borrowers, a well-documented family loan at a modest rate costs less and carries less downside than a 401(k) loan, but there are real cases where the 401(k) is the better call. Here is how the two actually compare, with the numbers each option hides.
How much you can actually borrow
A 401(k) loan is capped by law, not by how much you need. Under IRS rules, you can borrow the lesser of $50,000 or 50% of your vested account balance. If 50% of your vested balance is under $10,000, your plan may (but doesn't have to) let you borrow up to $10,000 instead. Borrow more than once in the trailing 12 months and the $50,000 ceiling drops by your highest outstanding balance during that period.
A family loan has no statutory cap. The only ceiling is what your relative is willing to lend and, in a handful of states, a usury limit on the interest rate you charge. That makes family loans the only option for borrowers who need more than $50,000 and don't have a six-figure 401(k) balance to draw against.
What it costs you
This is where the comparison gets misleading if you only look at the headline rate.
A 401(k) loan's "interest rate" is money you pay yourself, typically the plan's stated rate (often prime plus 1-2%). That sounds like a wash, but it isn't free. You repay the loan with after-tax paycheck dollars, and the interest you add back to the account gets taxed again when you eventually withdraw it in retirement. The principal isn't meaningfully double-taxed (you'd use after-tax income to repay any loan, bank or 401(k)), but the interest genuinely is taxed twice. The bigger cost is usually invisible: money pulled out of the market to repay the loan isn't growing while it's gone, and most plans freeze new contributions while a loan is outstanding, so you also lose part of an employer match.
A family loan's cost depends entirely on the rate you agree to. Charge too little or nothing, and the IRS can step in. Under the below-market loan rules, a family loan that charges less than the IRS's monthly Applicable Federal Rate (AFR) can trigger "imputed interest," meaning the IRS treats you as if the lender had actually received interest at the AFR and taxes them on it, even though no cash changed hands. The AFR changes every month and is published directly by the IRS, so check the current rate before you set terms rather than relying on a number from an old article. Our AFR and minimum interest calculator pulls the current month's published rates so you can set a compliant rate in minutes.
| 401(k) loan | Family loan | |
|---|---|---|
| Maximum amount | Lesser of $50,000 or 50% of vested balance | No legal cap (state usury limits may apply to the rate) |
| "Interest" | Paid to yourself, but taxed twice on the interest portion | Set by agreement; must meet or exceed AFR to avoid imputed interest |
| Approval | Automatic if plan allows loans | Depends entirely on the relationship and the lender's cash |
| Credit check | None | None |
| Shows on credit report | No | No, unless the loan goes to collections or court |
| Risk if you lose your job | Can trigger immediate tax and penalty (see below) | No tax event; relationship risk instead |
| Paper trail | Automatic, through the plan administrator | Only if you create one yourself |
The job-loss risk a 401(k) loan carries that a family loan never does
This is the single biggest reason to think twice about a 401(k) loan. If you separate from your employer, whether you quit, get laid off, or the plan terminates, with an outstanding loan balance, your plan can require immediate repayment. If you can't come up with the cash, the unpaid balance becomes a "deemed distribution" or "loan offset": taxable as ordinary income in that tax year, plus a 10% early-withdrawal penalty if you're under 59½, reported to the IRS on Form 1099-R.
The Tax Cuts and Jobs Act softened this somewhat. Instead of the old 60-day window, you now have until the due date (including extensions) of your federal tax return for the year of the offset, often well over a year, to roll over an amount equal to the offset into an IRA or a new employer's plan and avoid the tax hit. The catch: you have to come up with that money from somewhere else. If you just lost your job and already spent the loan proceeds, that outside cash may not exist.
A family loan carries no equivalent trap. Lose your job, and you still owe your relative the balance, but there's no IRS deadline, no 1099-R, and no penalty. The worst case is a hard conversation and a request to pause or restructure payments, which is exactly the kind of flexibility a family loan is suited for. Our guide on pausing a family loan during a hardship covers how to do that without the IRS treating the pause as a disguised gift.
Does either one hurt your mortgage application?
Neither shows up on a credit report, so neither directly dings your credit score. But they can both affect how a mortgage underwriter reads your finances, in different ways.
A 401(k) loan doesn't appear as external debt, but the monthly repayment reduces the take-home income an underwriter sees, which can affect your debt-to-income ratio depending on the lender and loan program. Underwriters may also ask why your retirement contributions dropped while the loan was outstanding.
A family loan creates a different problem: if a lender spots a large, undocumented deposit in your bank account, they may require you to prove it wasn't borrowed money being used to fake a bigger down payment, or they may require it to be documented as a bona fide loan with its own payment factored into your DTI. Our guide on family loan or gift for a down payment walks through exactly what documentation mortgage lenders want to see.
When the 401(k) loan is actually the better choice
It isn't always the wrong answer. A 401(k) loan makes more sense than a family loan when:
- You have no family member who can lend the amount you need, or asking would create more strain than the debt itself.
- Your job is genuinely stable and the risk of a surprise separation is low.
- You need the money for a short window and can repay well inside the five-year term (or longer, for a primary-residence purchase) without disrupting retirement contributions for long.
- You want zero relationship risk. Money problems are a leading source of family conflict, and some borrowers would rather risk their own retirement account than risk a parent or sibling relationship.
When the family loan wins
A family loan is usually the better deal when:
- You need more than $50,000, which a 401(k) loan can't provide regardless of your balance.
- Your job situation is uncertain. A family loan removes the single biggest risk of a 401(k) loan entirely.
- You want to keep your retirement investments working. Every dollar pulled from a 401(k) stops compounding until it's repaid.
- A relative is willing and able to lend at a reasonable rate. Set the rate at or above the current AFR, put it in writing, and you get the lower-cost option without an IRS problem on either side.
If you go this route, don't rely on a handshake. A signed promissory note with the rate, term, and payment schedule protects both of you and is what separates a real loan from something the IRS or a court could later call a gift. You can create a free family loan agreement in minutes, and track payments against the schedule from day one with Family Loan Tracker.
The bottom line
A 401(k) loan trades a tax-and-penalty risk for the appearance of borrowing from yourself at no real cost. A family loan trades that risk for a different one: the relationship. If your job is solid and you can repay fast, a 401(k) loan is a reasonable short-term tool. If you need more than a 401(k) can offer, or your income is at all uncertain, a documented family loan at a fair rate is usually the cheaper, safer choice.
This article is general information, not tax or legal advice. Rules on retirement plan loans and gift/imputed-interest treatment can be fact-specific; talk to a CPA or financial advisor before borrowing against either your 401(k) or a family relationship.
