What happens to a 403(b) loan before retiring if you leave with a balance?

"I'm paying the interest to myself, so the loan costs nothing"

Take $30,000 out of the market for five years. Assuming 5% a year, for illustration, that money would have grown about $1,500 a year. The interest you pay yourself covers only part of that gap, and the market might do better or worse, since investments can lose value.

There's a second cost people miss. Loan payments come out of after-tax pay, and the interest you send to your account gets taxed again when it leaves as income draws in retirement. The amount is small, but it's real, and we count it.

The size cap comes from section 72(p) of the tax code, and the IRS applies it to a 403(b) and to a governmental 457(b) alike. You can borrow the lesser of $50,000 or half your vested balance. Some plans allow up to $10,000 even when that is more than half. The usual term is five years, with level payments at least every quarter.

Rule of thumb: if you might leave school before the term ends, borrow only what you could repay from cash on your last day. Anything above that is a taxable distribution waiting to happen.

What the loan really gives up

How much the plan lets you borrow

"When I retire, I'll have 60 days to pay the loan back"

Not quite. The IRS treats a plan offset caused by leaving your job as a qualified plan loan offset. You can roll that amount into an IRA with your own cash until your tax-filing deadline for that year, extensions included. But the plan document decides when the offset happens. Some plans offset at the end of the next quarter, and some let retirees keep paying by bank draft. Ask for the rule in writing.

Put the loan dates on one calendar

List them in order. First comes the loan date and its five-year end date. Next is your last paycheck, when payroll deductions stop. Then the plan's offset date from its loan policy, which you should get in writing. After that, Form 1099-R arrives by January 31, showing code M for a qualified offset. The IRA rollover deadline comes last: the due date of that year's return, with extension.

The time crunch is real. The pension application, any unused-leave payout, Medicare enrollment and the last paycheck all land in the same few months. The rollover deadline is the one date nobody sends a reminder for.

Medicare adds another clock. The 2026 Part B premium is set from 2024 income, so an offset in your retirement year can raise the premium two years later, and a spouse's premium with it. Medicare calls the extra charge IRMAA.

Compare what an advisor charges to track these dates with the $5,814.40 Esther and Rick would lose in the next section. That cost comes from one missed rollover deadline on a $22,000 balance.

The dates, in calendar order

Why a later premium bump surprises people

"A small leftover balance won't change our tax bill"

Esther, 61, borrows $30,000 from her 457(b) for a new roof so the couple's $35,000 savings stays untouched (hypothetical, round numbers). Her husband Rick, 63, already retired as a district transportation supervisor and draws a pension. Eighteen months later Esther retires owing about $22,000, and the plan offsets it.

They had planned $205,000 of income that year: $50,000 pension, $35,000 salary and a $120,000 Roth conversion. The offset lands on top of all of it, so it's taxed at the household's highest rate. At an assumed 22%, $22,000 times 0.22 is $4,840 of federal tax. Some states tax it too; check your state's rules.

Then comes the IRMAA step. Joint income moves from $205,000 to $227,000, past the $218,000 line. Medicare uses that retirement-year income to set Rick's Part B premium two years later, not in the year of the offset. In that later year his premium goes from $202.90 to $284.10 a month. The $81.20 difference times 12 is $974.40 for the year.

The fix is simple, if you have the cash. Before their extended filing deadline, they move $22,000 from savings into an IRA in Esther's own name. Income drops back to $205,000, and the $5,814.40 of extra cost ($4,840 plus $974.40) disappears. Before Harbourfront Wealth Management suggests a Roth conversion amount for that year, it adds the loan payoff balance to the income projection. Our calculator can run this kind of arithmetic with your own numbers.

Look at the Roth conversion row in the table. Trimming the conversion to $100,000 brings income down to $207,000, which stays under the $218,000 line, so Rick keeps paying $202.90. The $4,840 of tax on the offset stays the same unless the offset itself shrinks.

Mistake to avoid: putting the $22,000 into Rick's IRA or the couple's joint savings doesn't count as Esther's rollover. Most of it becomes an excess contribution in Rick's IRA, taxed 6% a year until the custodian removes it. If the correction comes after Esther's extended deadline, she still owes tax on the full $22,000.

The bracket problem, in dollars

The fix, and the way it goes wrong

Does my answer change if I'm single or retiring at 55?

Yes. A single filer reaches the first IRMAA tier above $109,000, half the joint line. Leaving a 403(b) job before the year you turn 55 adds a 10% additional tax on the offset. An offset from a governmental 457(b) usually escapes that 10% tax whatever your age.

A single teacher with a $60,000 pension has less room before an offset pushes the Part B premium up. When both spouses are on Medicare, the surcharge hits twice, so the same $22,000 offset would cost two times $974.40.

Age works the same way. Leave at 54 and a $20,000 offset adds $2,000 on top of the income tax. Leave in the year you turn 55 or later and that extra tax goes away.

Bigger balances and bigger incomes make this worse. A school administrator near the top of a bracket, or a teacher married to a private-sector spouse with a large salary or company stock vesting that year, sees every offset dollar taxed at the highest rate. A $50,000 loan left unpaid is a much bigger problem than a $5,000 one.

Single filers and two-Medicare couples

Leaving at 54 versus 55

Run this checklist on your own plan

Check each item below before you sign the retirement papers. Then name the titling error to yourself: replacement money in a spouse's IRA or a joint account does not count as your rollover. Undoing it means the custodian removes an excess contribution, and you may still miss your own deadline.

• The plan's written rule on loans at separation, including the offset date
• The payoff balance projected to your last day of work
• Cash you could use to repay or replace it
• An IRA in your own name, opened before you retire
• That year's projected MAGI compared with $218,000 joint or $109,000 single

Where Harbourfront Wealth Management starts with a loan balance

Harbourfront Wealth Management would first pull your loan statement for the payoff balance and payment schedule. Then we read your plan's rule on what happens when you leave. Next we set that balance beside the year's pension, salary and any planned Roth conversion to see where income lands against the IRMAA line. The cost of this review is put in a signed agreement, so families see the fee before we start.