The S-corp health insurance deduction is one of the easiest deductions to lose without realizing it — and if you employ family, you may be losing it right now. Do you have a spouse, kids, or other family members who work in your S corp? Do you cover their health insurance? If you do, there's a snag you might hit if the paperwork is done incorrectly. Covering their insurance is fine — as long as you follow the rules. And this is a tricky one.
Get it wrong and you lose the deduction twice: once at the corporate level and once on their personal return. The money is simply gone.
Here's the rule. The IRS uses something called the Section 318 attribution rule. It says that certain family members are treated as owning the same stock you own. Your son works for you and owns zero percent of the company? Under Section 318, the IRS considers him a more-than-2% shareholder — the same as you. (Surprised? Most people are.)
That matters because more-than-2% shareholders don't get health insurance as a regular tax-free fringe benefit. They get it a different way. The premiums have to run through payroll. They get added to Box 1 of your family member's W-2. And then your family member deducts them on their own 1040.
If your bookkeeper or payroll company is treating your spouse or kids like regular W-2 employees when it comes to health insurance, the S-corp health insurance deduction is probably not being captured correctly.
When the setup is wrong, the damage happens on both sides of the return:
Section 318 attribution reaches further than most owners expect. The family members it applies to are your spouse, children, grandchildren, great-grandchildren, parents, and grandparents. If any of them work in your S corp and you're covering them on your health plan, it is worth taking a few minutes to confirm the setup is right.
I've seen this done incorrectly many times — I have 20 years of experience with S corp businesses, and this is a common mistake. It rarely gets caught until someone goes looking for it.
If it wasn't set up correctly in prior years, there's still time to fix it. The years 2022, 2023, and 2024 are generally still open for amended returns, which means the deduction isn't necessarily gone forever. Correcting the W-2 treatment and the personal return can recover an S-corp health insurance deduction you already thought you lost.
If you want to review how your S corp health setup is structured, let's get on a call.
The premiums must be paid by the S corporation and reported as taxable wages in Box 1 of the shareholder-employee's W-2. The shareholder then takes an above-the-line self-employed health insurance deduction on their personal 1040. The premiums are not subject to Social Security or Medicare (FICA) taxes when the plan covers the shareholder.
Section 318 treats certain family members as owning the stock you own. So even if your spouse, child, or parent owns zero percent of the company on paper, the IRS treats them as a more-than-2% shareholder — which changes how their health insurance must be handled.
Your spouse, children, grandchildren, great-grandchildren, parents, and grandparents. If any of them work in your S corp and are covered on your health plan, the more-than-2% shareholder rules generally apply to them.
The deduction can be lost twice — the S corporation loses its deduction for that family member's premiums, and the family member loses the self-employed health insurance deduction on their personal return. Neither is recovered unless the returns are corrected.
Often, yes. Tax years 2022, 2023, and 2024 are generally still open for amended returns. Correcting the W-2 reporting and the personal return can restore a deduction that was set up incorrectly in a prior year.
When premiums are paid under a plan covering the shareholder-employee, the added wages are included in Box 1 of the W-2 but are excluded from Boxes 3 and 5, so they are not subject to Social Security or Medicare taxes.
Keep your family-business tax setup tight with these related guides:
Disclaimer: This article is for general educational purposes only and does not constitute tax, legal, or accounting advice. The correct treatment of S-corp shareholder health insurance depends on your specific facts and circumstances. Please consult a qualified tax professional before filing or amending a return.