Every February, the same three emails hit HR inboxes: “My 1099-SA doesn’t match,” “Did the company contribution count toward my limit?,” and “I paid a bill from my HSA — is that deductible twice?” Most of the confusion lives on Form 8889.
What employees actually need from you
You usually don’t prepare their 8889 — but you do control the data trail:
- W-2 Box 12 code W — employer HSA contributions, which generally include amounts employees elect pre-tax through the cafeteria plan.
- Trustee statements — Form 5498-SA (contributions) and 1099-SA (distributions) come from the HSA custodian, not the employer’s imagination.
- Prior-year contribution timing — employees can make prior-year HSA contributions until the tax return due date (not including extensions); make sure payroll “tax year” tags are correct when someone asks for a March contribution to count as 2025.
Common mix-ups
- Paying a medical bill with an HSA and also deducting that bill as an itemized medical expense — that’s double-dipping.
- Assuming a spouse’s coverage details don’t affect the family contribution limit — they do.
- Forgetting that a non-HDHP spouse’s general-purpose FSA can spoil HSA eligibility for the household’s family-coverage strategy.
A useful one-liner for employees
“Your HSA custodian reports the money movement; Form 8889 is where you tell the IRS how that lines up with your HDHP coverage months.”
If you want fewer tickets, drop a short intranet note with custodian login links and last year’s contribution limit reminder. Tax season is not the moment for scavenger hunts.