What Is Form 8889-S? HSA Rules for Spouses on Joint Returns

Form 8889-S is not a separate IRS form. It is the label tax preparation software puts on the spouse’s copy of Form 8889 when a married couple files jointly and both spouses have their own Health Savings Account. The IRS requires a separate Form 8889 for each account holder, so software distinguishes the two by adding “-S” to the spouse’s version. The rules, line items, and calculations are identical to the standard Form 8889.¹

Why Two Forms on One Joint Return

An HSA belongs to one person. It cannot be jointly owned, even by spouses. When both partners on a joint return contributed to or took distributions from their own HSAs during the year, each one has to report their own activity on their own Form 8889. The primary taxpayer’s copy is filed as Form 8889. The spouse’s copy carries the “-S” suffix in most software so the IRS can tell them apart when the return is transmitted.¹

Each form must be filed if, during the tax year, that spouse:

Made contributions, or had contributions made on their behalf by an employer or anyone else
Took any distribution, even one used entirely for qualified medical expenses
Inherited an interest in an HSA
Also maintained an Archer MSA

Skipping the form when distributions were taken can lead the IRS to treat the entire withdrawn amount as taxable, plus a 20% additional tax on anything not used for medical care.²

How the Contribution Limit Works for Couples

The trickiest part of filing two 8889s comes from a rule that treats spouses as a unit for the contribution ceiling but as individuals for everything else. If either spouse has family HDHP coverage, both spouses are treated as having family coverage, and the family contribution limit applies to the two of them combined. For 2026, that combined family limit is $8,750. The self-only limit is $4,400.³

The family limit can be split between the two HSAs however the spouses agree. If they cannot agree, the split is 50/50. Each spouse then reports their allocated share on their own Form 8889, and each one’s contributions must stay within that share.⁴

The catch-up contribution works differently. Anyone 55 or older can add $1,000 above the regular limit, but that catch-up has to go into that person’s own HSA. A 56-year-old cannot deposit their $1,000 catch-up into a younger spouse’s account. If both spouses are 55 or older and both want the catch-up, both need their own HSA. That is one of the most common reasons couples end up with two accounts and, therefore, two forms to file.⁴

2026 HDHP Thresholds Each Spouse Tests Against

Contribution eligibility depends on being covered by a High Deductible Health Plan on the first day of each month. For 2026, an HDHP must have:

A minimum annual deductible of $1,700 for self-only coverage or $3,400 for family coverage
Maximum annual out-of-pocket expenses of $8,500 for self-only or $17,000 for family (excluding premiums)

On top of HDHP coverage, each spouse must independently meet the other eligibility tests on the first day of the month: no disqualifying non-HDHP coverage (dental, vision, disability, long-term care, and telehealth are fine), not enrolled in Medicare, and not claimed as a dependent on anyone else’s return.⁵ One spouse can be eligible while the other is not, and the form handles that month by month on each copy.

What Each Spouse Fills Out

Every Form 8889, whether it is the primary or the -S copy, has three parts. Each spouse works through their own.

Part I: Contributions and Deduction

Line 2 reports contributions that spouse made out of pocket during the year (or that someone other than an employer made on their behalf). Employer contributions and payroll deductions through a cafeteria plan go on Line 9 instead, not Line 2.¹ The form walks through eligible months and applicable limits, taking into account the agreed family-limit split if it applies, and produces a deduction on Line 13. That amount flows to Schedule 1 of the joint Form 1040. Each spouse’s deduction is calculated separately and added to the couple’s return.⁶

Part II: Distributions

Total distributions from that spouse’s HSA go on Line 14a. Amounts used for qualified medical expenses go on Line 15. The difference is the taxable portion, added to that year’s income on Schedule 1. Non-qualified amounts also carry a 20% additional tax on Lines 17a and 17b, unless the account holder was 65 or older, disabled, or the distribution was made after death.² Distributions come from one spouse’s HSA and are reported only on that spouse’s form; you never combine them.

Part III: Testing Period Failure

Part III applies only to a spouse who used the last-month rule or made a qualified HSA funding distribution from an IRA and then failed to stay HSA-eligible through the required testing period. If that happened to one spouse, that spouse completes Part III on their own copy. The other spouse leaves it blank.⁷

Documents Each Spouse Needs

Each HSA generates its own paperwork, and each spouse needs their own set to complete their own Form 8889:

Form 1099-SA from the HSA trustee, reporting total distributions and a distribution code⁸
Form 5498-SA from the trustee, reporting total contributions including any employer contributions⁹
Records of HDHP coverage for each month of the year

Trustees have until the end of May to send Form 5498-SA, so it may arrive after the April filing deadline. If a spouse’s copy has not arrived, year-end statements from the HSA provider and personal records can fill in the contribution figure.

Contribution Deadline

Contributions for a given tax year can be made up to the April 15 tax filing deadline of the following year without needing an extension. A spouse who realizes at filing time that they have room under the family split can make a last-minute contribution before filing, and it counts for the prior year.²

Where Couples Get Tripped Up

Excess Contributions Across Two Accounts

Because the family limit covers both HSAs together, it is easy for a couple to exceed it without either spouse individually going over what looks like a plausible number. Contributions above the combined family limit trigger a 6% excise tax each year the excess remains in either account.²

The fix is to withdraw the excess (plus earnings on it) before the tax return due date, including extensions. The withdrawn earnings must be reported as income for the year of the over-contribution. Missing that window means the 6% tax applies year after year until the excess is used up against a future year’s limit or withdrawn.

One Spouse Enrolling in Medicare

When one spouse turns 65 and enrolls in Medicare, that spouse’s HSA contribution limit for the year is prorated to cover only the months before Medicare enrollment. The other spouse, if still HSA-eligible, can keep contributing under the ordinary rules. If the Medicare-enrolled spouse delayed applying and later got retroactive coverage, contributions made during the retroactive period become excess contributions. Once a spouse reaches 65, the 20% additional tax on non-qualified distributions from their HSA no longer applies, though regular income tax still does.²

Filing Both Forms Together

Both Form 8889 copies are attached to the same joint Form 1040 (or 1040-SR or 1040-NR).⁷ Tax software handles the “-S” labeling and the attachment automatically. If you file on paper, include both forms with the mailed return. Each spouse’s deduction from Line 13 and any taxable distribution or additional tax from Part II flows to the shared Schedule 1 and Schedule 2, so the two forms feed into a single joint tax calculation even though they are prepared separately. Blank copies of Form 8889 and its instructions are available on the IRS website.¹⁰

1
Internal Revenue Service. Instructions for Form 8889 (2025)
2
Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans
3
Internal Revenue Service. Revenue Procedure 2025-19 – 2026 Inflation Adjusted Amounts for Health Savings Accounts
4
Internal Revenue Service. IRS Courseware – Rules for Married People
5
Office of the Law Revision Counsel. 26 USC 223 – Health Savings Accounts
6
Internal Revenue Service. Form 8889 (2025)
7
Internal Revenue Service. 2025 Instructions for Form 8889 – Health Savings Accounts
8
Internal Revenue Service. Instructions for Forms 1099-SA and 5498-SA
9
Internal Revenue Service. Form 5498-SA (Rev. December 2026) HSA, Archer MSA, or Medicare Advantage MSA Information
10
Internal Revenue Service. About Form 8889, Health Savings Accounts (HSAs)