Yes, the interest you pay on a 401(k) loan does go back to you. Every dollar of interest is deposited into your own retirement account and reinvested alongside your existing balance, not paid to a bank or outside lender. That makes the loan genuinely different from a credit card or personal loan, where interest is a pure cost you never see again. But the “paying yourself” framing hides two real expenses: the interest is effectively taxed twice, and the money you borrow stops earning market returns while it’s out of the account. For most borrowers, those two costs outweigh the benefit of keeping the interest inside their own ecosystem.
How the Money Flows Back Into Your Account
When you take a 401(k) loan, the plan sells enough of your investments to fund it, and those assets leave the market. Repayments come out of your paycheck automatically, and both the principal and the interest are deposited back into your account and reinvested according to your existing fund selections. You’re simultaneously the borrower and the lender, with your remaining balance serving as collateral.
Payments have to be made at least quarterly on a level amortization schedule, and the loan generally has to be repaid within five years. Loans used to buy a primary residence can run longer, with the maximum term set by the plan.1Office of the Law Revision Counsel. 26 USC 72 – Annuities; Certain Proceeds of Endowment and Life Insurance Contracts
How Your Interest Rate Is Set
Federal rules require that the interest rate on a 401(k) loan be “reasonable,” meaning it should be comparable to what a bank would charge on a similar fully secured loan.2U.S. Department of Labor. Advisory Opinion 1995-17A In practice, most plan administrators start with the prime rate and add a margin of 1% to 2%. With the prime rate at 6.75% as of March 2026, that puts a typical 401(k) loan rate in the 7.75% to 8.75% range.3Federal Reserve Bank of St. Louis. Bank Prime Loan Rate (DPRIME)
Your plan’s specific formula appears in the Summary Plan Description.4Internal Revenue Service. Retirement Topics – Plan Loans Some plans lock the rate at origination; others adjust it over time. Beyond interest, many plans also charge a one-time origination fee and ongoing maintenance fees, often totaling $50 to $100 or more. Those fees don’t come back to you, and they cut directly into whatever benefit you get from paying interest to yourself.
The Catch: You Pay That Interest With After-Tax Dollars
Here’s where the story gets less rosy. Loan repayments, interest included, come out of your paycheck with after-tax dollars. Years later, when you withdraw that money in retirement, the entire distribution is taxed again as ordinary income. The interest portion effectively gets taxed twice: once when you earned the wages to make the payment, and again when you eventually pull the money out.
The dollar impact is usually smaller than it sounds. On a $10,000 loan at 8% for a borrower in the 24% bracket, the extra tax attributable to the interest works out to a few hundred dollars over the life of the loan. That’s still less than what you’d pay a bank on a comparable personal loan, where every cent of interest leaves your pocket permanently. But the double taxation grows with the size of the loan and the length of time you carry it.
One more detail: interest on a 401(k) loan is never deductible. Unlike mortgage interest, you can’t write any of it off, even if you used the loan to buy a house.5Internal Revenue Service. Considering a Loan From Your 401(k) Plan
The Cost Most Borrowers Overlook
The bigger issue with “paying interest to yourself” is what your money isn’t doing while it’s out on loan. When the plan liquidates investments to fund the loan, that cash earns whatever fixed rate is on the loan instead of whatever your stock and bond funds would have returned.
If your loan rate is 8% and your investments would have averaged 10%, you’re giving up 2% a year on the borrowed amount. On a $25,000 loan over five years, that gap can add up to thousands of dollars in forgone growth, and the loss compounds over every year between now and retirement. If your investments happen to underperform the loan rate during the borrowing period, you come out ahead. But over most five-year windows, stock market returns have exceeded typical 401(k) loan rates, so the odds usually work against the borrower.
This opportunity cost never shows up on a statement as a fee. It’s invisible, which is precisely why it gets missed. For younger workers with decades of compounding still ahead of them, it’s often the single largest real cost of borrowing from a 401(k), well beyond the double-taxation issue and any origination fees.
What Happens If You Miss Payments
Missing a payment doesn’t immediately trigger a tax problem. Most plans include a cure period that runs through the end of the calendar quarter after the quarter in which you missed the payment. A payment due in February, for example, would have a cure period extending through June 30.6Internal Revenue Service. Issue Snapshot – Plan Loan Cure Period Catch up within that window and the loan stays in good standing.
If the cure period passes, the entire remaining balance plus accrued interest becomes a “deemed distribution.” The IRS treats it as if you had taken that amount out of your retirement account.7Internal Revenue Service. Deemed Distributions – Participant Loans You’ll owe ordinary income tax on the full balance, and if you’re under 59½, an additional 10% early distribution penalty on top.5Internal Revenue Service. Considering a Loan From Your 401(k) Plan On a $30,000 outstanding balance, a borrower under 59½ in the 24% bracket could face roughly $10,200 in combined taxes and penalties.
What Happens If You Leave Your Job
This is where most 401(k) loans go wrong. If you quit, get laid off, or otherwise separate from your employer, the plan can require you to repay the full outstanding balance.4Internal Revenue Service. Retirement Topics – Plan Loans Payroll deductions stop the day you leave, so you have to find the cash elsewhere. If you can’t, the unpaid balance becomes a taxable distribution subject to the same income tax and possible 10% penalty.
There is a safety valve. If your plan offsets the loan balance against your account (a “qualified plan loan offset”), you can roll an equivalent amount into an IRA or another eligible retirement plan by your tax filing deadline, including extensions. That typically gives you until October 15 of the following year.8Internal Revenue Service. Plan Loan Offsets Completing the rollover avoids both the income tax and the early distribution penalty. The practical problem is finding that cash, since the plan has already used your account balance to settle the loan.
The combination of losing a paycheck and suddenly owing taxes on an outstanding loan hits harder than most borrowers expect. If your job situation is uncertain, that risk deserves as much weight as the interest rate itself when you’re deciding whether the “paying yourself” pitch is really worth it.