47% of U.S. Workers Struggle to Save for Retirement Because of Health Costs. One Social Security Filing Mistake at 67 Could Trigger an Annual 6% HSA Tax

Health costs are squeezing retirement plans long before anyone retires. In WTW’s Global Benefits Attitudes Survey, 47% of U.S. workers said healthcare costs get in the way of their retirement saving.

That pressure is a big reason a health savings account (HSA) is so useful. Money goes in tax-free, grows tax-free and comes out tax-free for medical bills. Picture a common setup. An operations manager keeps working past 65. He stays on his employer’s HSA-eligible high-deductible plan and keeps putting $500 a month into his HSA. At 67, he finally applies for Social Security.

He figures he’s done everything right. But applying for Social Security can turn months of HSA contributions into a tax problem after the fact, even though he was still working and covered by his employer’s health plan.

Filing for Social Security Can Backdate Your Medicare

If you are 65 or older when you apply for Social Security retirement benefits, you are generally enrolled in premium-free Medicare Part A automatically. The two are tied together, so collecting the monthly check means taking Part A.

Part A comes with a twist. For someone applying at 67, coverage generally goes back six months before the application, even if they didn’t request it. That means our manager could discover he’s had Medicare for half a year without realizing it. At $500 a month, he may have contributed $3,000 to his HSA during months he was no longer eligible.

Backdated Coverage Turns Good Deposits Into Excess Ones

Under federal tax law, your HSA contribution limit is zero for the first month you are entitled to Medicare and for each month after. The IRS applies that rule to retroactive coverage too. You count as a Medicare enrollee for those backdated months, even though you had no idea at the time.

Those backdated months can leave him with excess HSA contributions. His annual contribution limit shrinks because Medicare coverage makes him ineligible for those months, and employer deposits count toward the same limit. If his total contributions exceed what’s allowed for the year, the excess loses its tax advantage and can trigger additional taxes.

How big the problem gets depends on two things: how far back Part A goes and how much went in during that window. A worker putting in the family maximum has much more at stake than someone saving a modest amount.

A 6% Tax That Comes Back Every Year

Leave excess HSA contributions unresolved, and the IRS can impose a 6% annual tax on the excess that remains, subject to the account’s year-end value. The charge can return in later years until the excess is corrected. It is one of several subtle IRS rules. These triggers can drain a retirement account over time (we mapped out nine of them in a free tax trap guide if you want the full set).

The fix is simple if you catch it in time. Take out the excess contributions, plus anything they earned, by the due date of your tax return, including extensions, for the year you made them. You report those earnings as other income, and the excise tax goes away on the amount you removed.

How to Shut Off HSA Contributions Before You File

1. Stop your own payroll contributions early. If you’re applying for Social Security after 65, Medicare recommends stopping HSA contributions six months beforehand. That gives you room for Part A’s retroactive coverage without creating an unexpected tax problem.
2. Stop employer contributions as well. Employer deposits count against your zero limit just like yours do, so ask HR to turn them off on the same schedule.
3. Line up your filing date with payroll. Choose your application month first, then make sure your last HSA payroll deduction goes through before the backdated window opens.

The money you have already saved is not affected by this. The balance is still yours, and withdrawals for qualified medical expenses stay tax-free after Medicare starts. Once you reach Medicare age, the 20% penalty on non-medical withdrawals no longer applies, although those withdrawals are still taxed as ordinary income. The only thing that stops is new contributions.

Plan the HSA Shutoff Before You Hit Submit

The time to protect your HSA is before you apply for Social Security. Work backward from your planned filing date and make sure both you and your employer stop contributing early enough. That one step protects years of tax-free savings from a penalty that keeps coming back.

The withdrawal deadline offers a clean way to fix it for those who have already filed and kept contributing. Medicare start dates and employer plan setups vary from person to person, so a quick call to Social Security to confirm when your own Part A would begin can save you from an expensive mistake.

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