You can use your HSA for your girlfriend’s medical expenses tax-free only if she qualifies as your tax dependent under a relaxed version of the federal “qualifying relative” tests, or if you are already legally married under any state’s law, including through common-law marriage. Federal law limits tax-free HSA distributions to expenses for the account holder, a legal spouse, and tax dependents.1Office of the Law Revision Counsel. 26 USC 223 – Health Savings Accounts A girlfriend fits none of those categories by default. Spending HSA money on someone outside them triggers ordinary income tax plus a 20% penalty on the amount withdrawn.
The Three Tests Your Girlfriend Must Pass
For HSA purposes, your girlfriend can count as a “qualifying relative” dependent, and the statute waives three of the tests that would otherwise apply on a standard tax return: the gross income limit, the joint return restriction, and the rule blocking dependency when another taxpayer could also claim her.1Office of the Law Revision Counsel. 26 USC 223 – Health Savings Accounts What remains is a shorter list, but each item is strict.
She Lives With You All Year
Your girlfriend must share your home as a member of your household for the entire tax year, not most of it.2Office of the Law Revision Counsel. 26 USC 152 – Dependent Defined Brief absences for vacation or a hospital stay generally don’t break the year, but she can’t keep a separate primary residence for any part of it.
There is one legal wrinkle: the relationship cannot violate local law.3Internal Revenue Service. Publication 501, Dependents, Standard Deduction, and Filing Information In practice this affects situations where one partner is still legally married to someone else. A small number of states retain anti-cohabitation statutes, though enforcement is essentially nonexistent.
You Pay More Than Half Her Support
You must provide over half of your girlfriend’s total support for the calendar year.2Office of the Law Revision Counsel. 26 USC 152 – Dependent Defined Support includes housing, food, clothing, transportation, education, and medical care. Add up everything spent on her from all sources, including her own spending, and confirm your share crosses 50%.
Keep documentation: bank statements, receipts, and lease agreements showing who paid what. If your girlfriend covers a large share of her own living costs, you probably fail this test even if she lives with you full-time.
She Isn’t Someone Else’s Qualifying Child
Your girlfriend cannot be the qualifying child of any other taxpayer for the same year.2Office of the Law Revision Counsel. 26 USC 152 – Dependent Defined This usually matters only if she is young enough to still be claimed by a parent. Under 19, or under 24 and a full-time student, plus claimed by a parent as a qualifying child, and she is out.
Her Income Doesn’t Disqualify Her
This is the most common misconception. On a regular tax return, a qualifying relative must earn less than the exemption amount — $5,300 for 2026 — to count as a dependent.4Internal Revenue Service. Revenue Procedure 2025-32 The HSA statute explicitly removes that income test when defining who counts for qualified medical expense purposes.1Office of the Law Revision Counsel. 26 USC 223 – Health Savings Accounts
Your girlfriend could earn $50,000 a year and still be eligible for tax-free HSA distributions, provided she lives with you all year, you supply more than half her support, and she isn’t anyone’s qualifying child. The same waiver removes the joint return restriction, so even a joint filing with someone else doesn’t automatically disqualify her.
If You’re Already Legally Married Without Realizing It
A legal spouse qualifies for tax-free HSA withdrawals automatically. No dependency analysis, no residency count, no support math. And that status may already apply to you: if you live in a state that recognizes common-law marriage and your relationship meets its criteria, the IRS treats you as married for every federal tax purpose, including HSAs.5Internal Revenue Service. Revenue Ruling 2013-17
Common-law marriage generally requires three things: a mutual agreement to be married, cohabitation as a married couple, and holding yourselves out publicly as married. Roughly nine jurisdictions still allow new common-law marriages, with varying requirements; several additional states recognize ones formed before a cutoff date.
Once the marriage exists, the IRS continues to recognize it even after you move to a state that requires a ceremony.5Internal Revenue Service. Revenue Ruling 2013-17 Confirming that status, where it applies, is the cleanest route to HSA eligibility.
Domestic Partnerships and Civil Unions Don’t Count
State or city recognition of a domestic partnership or civil union does not make your partner a spouse under federal tax law. Treasury regulations define “spouse” as an individual lawfully married to another individual, where the marriage is recognized by the state where it was entered into.6eCFR. 26 CFR 301.7701-18 – Definitions; Spouse, Husband and Wife A registered domestic partnership, however long-standing, doesn’t clear that bar.
The practical result: a domestic partner is eligible for tax-free HSA distributions only if she independently passes the dependent tests above. Employer health coverage that includes her doesn’t change her federal tax status for HSA purposes.
What the HSA Can Cover Once She Qualifies
If your girlfriend qualifies as your dependent or as your spouse, the medical expenses eligible for you are eligible for her. The IRS defines qualified medical expenses broadly to include costs of diagnosing, treating, or preventing disease and costs affecting any part or function of the body.7Internal Revenue Service. Publication 502, Medical and Dental Expenses Common examples:
- Doctor, dentist, chiropractor, and specialist visits
- Prescription drugs and insulin (most over-the-counter drugs qualify only when prescribed)
- Eye exams, glasses, contacts, and corrective eye surgery
- Dental cleanings, fillings, braces, extractions, and dentures
- Hearing aids, batteries, and repairs
- Mental health care from psychologists and psychiatrists
- Crutches, blood sugar monitors, and other durable medical equipment
Cosmetic procedures, gym memberships, and general health supplements generally don’t qualify. Publication 502 has the detailed list.
What It Costs If You Get It Wrong
Use HSA funds on your girlfriend when she doesn’t qualify, and the IRS treats the whole distribution as taxable income at your ordinary rate.8Internal Revenue Service. Publication 969, Health Savings Accounts and Other Tax-Favored Health Plans On top of that sits an additional 20% tax on the non-qualifying amount.9Internal Revenue Service. Instructions for Form 8889
Take a $3,000 withdrawal in the 22% bracket that turns out not to qualify: $660 in income tax plus a $600 penalty, for $1,260 in extra taxes on that single distribution. The 20% penalty drops away after you turn 65, become disabled, or die, though the income tax still applies to non-qualifying distributions.8Internal Revenue Service. Publication 969, Health Savings Accounts and Other Tax-Favored Health Plans
Fixing a Mistaken Distribution
If you paid your girlfriend’s medical bills from the HSA and later realize she didn’t qualify, you may be able to return the money and avoid both the income tax and the 20% penalty. The IRS allows repayment of mistaken distributions when there is clear and convincing evidence the withdrawal happened because of a reasonable mistake of fact, such as a genuine belief she met the dependency requirements.10Internal Revenue Service. Notice 2004-50
The deadline to return the money is April 15 of the year after you first knew or should have known the distribution was a mistake.10Internal Revenue Service. Notice 2004-50 A timely repayment isn’t included in gross income, isn’t hit with the 20% penalty, and isn’t treated as an excess contribution.
One catch: your HSA trustee or custodian isn’t required to accept a returned distribution.11Internal Revenue Service. Instructions for Forms 1099-SA and 5498-SA Contact the administrator quickly. If they accept the repayment, they can rely on your statement that the distribution was a mistake.
Why Unmarried Couples Can Save More
Married spouses who are both covered under a family high-deductible health plan have to split the family contribution limit between them.1Office of the Law Revision Counsel. 26 USC 223 – Health Savings Accounts Unmarried partners don’t. Because domestic partners aren’t spouses under federal tax law, each partner who independently meets HSA eligibility can open a separate account and contribute up to the full family limit.
For 2026, the family HSA contribution limit is $8,750 and the self-only limit is $4,400.12Internal Revenue Service. Revenue Procedure 2025-19 Two unmarried partners both covered under the same family HDHP, both HSA-eligible, could contribute up to $17,500 combined. Each partner 55 or older can add a $1,000 catch-up on top.
Note the tension. To open her own HSA, your girlfriend must be covered under a qualifying HDHP, have no disqualifying coverage, not be enrolled in Medicare, and not be claimed as a dependent on anyone else’s return.8Internal Revenue Service. Publication 969, Health Savings Accounts and Other Tax-Favored Health Plans If you claim her as your dependent so her medical bills qualify for your HSA, she loses the ability to fund her own. Depending on income and expenses, keeping two separate HSAs and skipping the dependent claim may save more than pooling everything through yours.