Taking a loan from your 401(k) does not, by itself, affect your taxes. As long as the loan follows the rules in Internal Revenue Code Section 72(p), the money leaves your account tax-free and you owe nothing to the IRS when you borrow. The tax consequences show up only if something goes wrong: a missed payment, a job change with an unpaid balance, or the quieter cost of pulling money out of a tax-deferred account for several years.
When a 401(k) Loan Stays Tax-Free
Federal tax law sets three conditions. Meet all three and the loan is treated as a loan. Miss any one and the IRS treats the outstanding balance as a distribution.1Internal Revenue Service. 401(k) Plan Fix-It Guide – Participant Loans Don’t Conform to the Requirements of the Plan Document and IRC Section 72(p)
The first is a borrowing cap. You can take the lesser of $50,000 or half your vested balance. If half your vested balance is below $10,000, the plan may let you borrow up to $10,000, but it is not required to.2Internal Revenue Service. Retirement Topics – Plan Loans The $50,000 ceiling is not refreshed with each new loan. It is reduced by the highest outstanding balance you carried in the previous 12 months, minus what you still owe on the day of the new loan.3Office of the Law Revision Counsel. 26 USC 72 – Annuities; Certain Proceeds of Endowment and Life Insurance Contracts If your employer sponsors more than one plan, or is part of a controlled group, loan balances across those plans are added together against the single $50,000 cap.4Internal Revenue Service. Issue Snapshot – Borrowing Limits for Participants With Multiple Plan Loans
The second is a five-year repayment deadline. Loans used to buy a primary residence are exempt from the five-year rule; the plan document sets the term for those.3Office of the Law Revision Counsel. 26 USC 72 – Annuities; Certain Proceeds of Endowment and Life Insurance Contracts
The third is a payment schedule. You have to make substantially level payments of principal and interest at least quarterly across the life of the loan.5Internal Revenue Service. Retirement Plans FAQs Regarding Loans
What a Default Costs in Taxes
If you miss a required payment and let the plan’s grace period expire, the entire unpaid balance becomes a “deemed distribution.” Your plan administrator reports it on Form 1099-R, and the full amount is taxed as ordinary income in that year.2Internal Revenue Service. Retirement Topics – Plan Loans
A detail worth knowing: the tax event does not erase the debt. Even after the IRS treats the balance as distributed, the plan can keep demanding repayment, and the deemed-distributed amount stays on the books until it is repaid or offset.6Internal Revenue Service. Fixing Common Plan Mistakes – Plan Loan Failures and Deemed Distributions
If you are under 59½ when the default happens, the IRS tacks on a 10% early withdrawal penalty.7Internal Revenue Service. Exceptions to Tax on Early Distributions For a borrower in the 22% or 24% federal bracket, the combined tax and penalty can reach 32% to 34% of the balance before state taxes enter the picture. A $20,000 loan can produce a tax bill north of $6,000.
Leaving Your Job With a Balance Outstanding
Separating from your employer with an unpaid loan creates a specific kind of default called a plan loan offset. The plan reduces your account by what you owe, and that offset counts as a distribution. But if it qualifies as a “qualified plan loan offset” (QPLO), you have until the due date of your federal tax return for that year, including extensions, to roll the offset amount into an IRA or another qualified plan using cash from any source.8Internal Revenue Service. Plan Loan Offsets For most people filing an extension, that stretches the deadline to roughly mid-October of the following year.
Miss the window and the full offset becomes taxable income, with the 10% penalty attached if you are under 59½.9Federal Register. Rollover Rules for Qualified Plan Loan Offset Amounts
The “Double Taxation” Claim, Clarified
You will see it said that 401(k) loan repayments are taxed twice because you repay with after-tax dollars and then pay tax again at retirement. The claim is mostly wrong, and the correct version matters when you are weighing the real cost.
The borrowed principal leaves your account tax-free. You received pre-tax dollars without paying tax. You then repay with after-tax dollars, which is the first time tax has actually hit that money. When you withdraw it in retirement, you pay tax again. Add it up and the principal is taxed once, which is the same number of times it would have been taxed had you never borrowed.
The interest is a different story. You pay interest into the account with after-tax dollars, and when you later withdraw those interest dollars in retirement, they are taxed as ordinary income. That piece genuinely is taxed twice. On a $20,000 loan at 8.5% over five years, the interest might total around $4,600, so the extra tax is real but a long way from the “whole balance gets double-taxed” version.
Loan repayments, including the interest, are not deductible.5Internal Revenue Service. Retirement Plans FAQs Regarding Loans
The Tax Cost You Do Not See on a Return
While a loan is outstanding, the borrowed money sits outside the market. You replace whatever your investments would have earned with a fixed-rate loan to yourself. If your fund mix would have returned 10% in a given year and your loan rate is 8.5%, you lose the gap on the borrowed amount, and that gap would otherwise compound tax-deferred for decades. On a $25,000 loan repaid over five years, even a two-percentage-point drag works out to thousands of dollars in lost tax-deferred growth by retirement. The earlier in your career you borrow, the more that loss compounds.
There is also a contribution problem. Some plans suspend new elective deferrals while a loan is outstanding. If yours does, you lose the tax deduction (or the Roth tax-free growth) on every dollar you cannot contribute during the repayment period. For 2026, the elective deferral limit is $24,500, with a $7,500 catch-up for participants 50 and older.10Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026; IRA Limit Increases to $7,500 If stopping contributions also means losing your employer match, that match is gone for good, and no interest rate you pay yourself can offset it. The plan’s summary plan description will tell you whether contributions are suspended during a loan.
Disaster-Related Relief
Under the SECURE 2.0 Act, plans may offer higher loan limits and extended repayment periods for participants affected by a federally declared disaster. This is optional for the plan, not automatic. If your plan has adopted the provision, the expanded terms can keep a loan from slipping into default and triggering the tax consequences above. Ask your plan administrator whether the relief applies to your situation before assuming it does.