Under federal law, domestic partner tax rules start from a single premise: the IRS does not treat a registered domestic partnership as a marriage, regardless of what your state calls it. You and your partner each file your own federal return, and neither of you can use Married Filing Jointly or Married Filing Separately.1Internal Revenue Service. Answers to Frequently Asked Questions for Registered Domestic Partners and Individuals in Civil Unions That one rule cascades into almost every other part of your tax picture, from filing status and employer health benefits to estate planning and retirement accounts.
Which Filing Status You Use
Most domestic partners file as Single. The 2026 standard deduction for a Single filer is $16,100.2Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Head of Household is the better status when you qualify, with a $24,150 standard deduction for 2026 and wider brackets that lower your effective rate on the same income.
Three conditions must all be met to file as Head of Household:3Internal Revenue Service. Publication 501, Dependents, Standard Deduction, and Filing Information
- You were unmarried on December 31. A registered domestic partnership is not a marriage for federal purposes, so this test is met automatically.
- You paid more than half the cost of keeping up the home for the year. Those costs include rent or mortgage payments, property taxes, insurance, utilities, and food eaten in the home.
- A qualifying person lived with you more than half the year. That is usually a dependent child. Your partner counts only if they pass the qualifying relative tests below.
If your partner does not qualify as your dependent but you have a child or other relative who does, you can still file as Head of Household through that person. Keep documentation showing you paid the majority of household costs.
Claiming Your Partner as a Dependent
A domestic partner can only be claimed under the qualifying relative rules. Four tests all have to be satisfied:4Office of the Law Revision Counsel. 26 USC 152 – Dependent Defined
- Member of household. Because your partner is not related to you by blood or marriage, they must live with you as a member of your household for the entire year. Temporary absences for travel or medical care generally do not break this, but an extended separation can.
- Gross income. Your partner’s gross income for the year must be less than the exemption amount, which was $5,200 for the 2025 tax year and is adjusted for inflation. A partner working full time will almost certainly exceed this.3Internal Revenue Service. Publication 501, Dependents, Standard Deduction, and Filing Information
- Support. You must provide more than half of your partner’s total support for the year, counting housing, food, clothing, medical care, and education. Money your partner earns but saves rather than spends does not count toward their own support.
- Not a qualifying child. Your partner cannot already be a qualifying child of someone else.
One more catch on the member-of-household test: the IRS can deny the dependent claim if the living arrangement violates local law. Almost no jurisdiction enforces cohabitation restrictions today, but the provision is still on the books.
What does claiming your partner actually get you? The personal exemption deduction is $0 under current law, so the dependent claim by itself does not shrink your taxable income the way it did before 2018.2Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 The value comes from what dependent status unlocks: Head of Household filing, exclusion of employer-provided health coverage from your wages, and deductibility of medical expenses you pay for your partner. Together, those can be worth thousands a year.
Employer Health Coverage and Imputed Income
When your employer covers your domestic partner on your health plan, the fair market value of that coverage is generally added to your taxable wages as imputed income. It lands in Box 1 of your W-2 alongside your regular pay, and you owe federal income tax plus Social Security and Medicare tax on it. The cost hits every paycheck, not just at filing. Married employees covering a spouse owe nothing extra on the same benefit.
If your partner qualifies as your tax dependent, the imputed income disappears. Employer-provided health coverage for an employee’s dependents is excluded from gross income.5eCFR. 26 CFR 1.106-1 – Contributions by Employer to Accident and Health Plans Your employer will usually ask you to certify your partner’s dependent status before removing the imputed income from your wages. If your partner stops qualifying during the year, imputed income restarts for the remaining pay periods.
The definition of “dependent” for this purpose is broader than the general rule. Federal regulations drop the gross income test when deciding whether someone qualifies for the employer health benefit exclusion.5eCFR. 26 CFR 1.106-1 – Contributions by Employer to Accident and Health Plans Your partner still has to live with you all year and still needs more than half their support from you, but they can earn well over the usual $5,200 threshold and still qualify. The same broader definition applies to medical expenses you pay for your partner, which you can include when calculating your own medical expense deduction (subject to the 7.5% of AGI floor). Keep receipts showing you actually paid.
Sharing a Home: Mortgage Interest and Property Taxes
Because you file separately, income is taxed to whoever earned it, and deductions follow the person legally responsible who actually paid. Nothing about pooling money in a joint account changes that.
Mortgage interest is deductible only by someone who is legally liable on the debt and actually made the payments. If both of you are on the note, each of you deducts the share you actually paid. Sixty/forty payments produce a sixty/forty split on your Schedule A entries. If only one partner is on the mortgage, only that partner can deduct the interest, even if the other contributed cash toward the payments (money that becomes a gift, discussed below). When both partners are liable but only one gets the Form 1098, the IRS says to attach a statement to your paper return showing how the interest was split.6Internal Revenue Service. Publication 936, Home Mortgage Interest Deduction
Property taxes work the same way. The person legally liable for the tax and who paid it takes the deduction. Bank statements or canceled checks establish which account each payment came out of.
Community Property States: California, Nevada, and Washington
Three states treat registered domestic partners the same as spouses for community property purposes: California, Nevada, and Washington.7Internal Revenue Service. Publication 555, Community Property If you’re registered in one of these states, federal tax law requires you to follow community property rules on your separate federal returns. Each partner reports half of the couple’s combined community income, no matter who actually earned it.
Community income generally covers wages, self-employment earnings, and investment income earned while domiciled in the state. Separate property income, from assets you owned before the partnership or received by gift or inheritance, stays on the individual partner’s return.
You file Form 8958 with your federal return to show how each income item and each dollar of withholding was allocated between the two of you.8Internal Revenue Service. Form 8958 – Allocation of Tax Amounts Between Certain Individuals in Community Property States Each partner gets credit for half of the federal income tax withheld on community wages. The form walks through wages, interest, self-employment income, withholding, and estimated tax payments line by line.
Gifts and Transfers Between Partners
Married couples get an unlimited marital deduction, so one spouse can transfer any amount to the other during life or at death with no gift or estate tax. Domestic partners have none of that. Every transfer between partners is treated the way transfers between strangers are treated.9Office of the Law Revision Counsel. 26 USC 2056 – Bequests, Etc., to Surviving Spouse
You can give your partner up to $19,000 in 2026 (the annual exclusion) without filing a gift tax return or owing tax. Above that, you file Form 709, but no gift tax is actually due until your cumulative lifetime gifts exceed the $15,000,000 basic exclusion.10Internal Revenue Service. Whats New – Estate and Gift Tax The trap most couples miss: if one partner pays the whole mortgage on a jointly owned home, the portion attributable to the other partner’s ownership share is technically a gift. Same with paying your partner’s credit cards, student loans, or car note. Small amounts rarely cause trouble, but large ongoing transfers can chew through your lifetime exclusion over time.
At death, everything a partner leaves to the survivor counts in the taxable estate. There is no marital deduction to shield it. The $15,000,000 basic exclusion covers most estates, but partners with combined assets approaching that figure cannot pool their exclusions the way spouses can, because portability of the unused exclusion is only available to a surviving spouse.
Retirement Accounts and Social Security
Federal retirement rules are built around marriage, and domestic partners sit outside most of the automatic protections.
A married couple can fund a spousal IRA for a non-earning spouse based on the working spouse’s income. Domestic partners cannot.11Internal Revenue Service. Retirement Topics – IRA Contribution Limits If your partner has no earned income, they generally cannot contribute to a traditional or Roth IRA at all.
A married spouse is typically the automatic beneficiary of an employer 401(k), and the plan needs the spouse’s written consent to name anyone else. Domestic partners have no such default. If your partner never names you on the beneficiary form, or the form is lost during a job change, plan assets can pass to a default beneficiary such as a parent or the estate. Update beneficiary forms and keep copies.
Social Security follows the same pattern. Married spouses can claim benefits on each other’s earnings record, including survivor benefits. Domestic partners generally cannot. The Social Security Administration has recognized some non-marital same-sex relationships in limited cases, mainly where unconstitutional state laws previously prevented the couple from marrying.12Social Security Administration. What Same-Sex Couples Need to Know If that might apply to you, contact SSA directly. Otherwise, each partner’s benefit depends entirely on their own work history.
Earned Income Tax Credit With Kids in the Home
Each partner’s EITC eligibility is decided independently on their own return. If you have a qualifying child living with you, you claim the EITC on your return based on your own earned income, even though your partner also lives in the home.13Internal Revenue Service. Other EITC Issues
When both partners have qualifying children, each of you can potentially claim the credit based on your own child. Two kids in the home can mean each parent claims one. Both partners cannot claim the same child. If they do, tiebreaker rules apply: the child goes to the parent they lived with longer during the year, or to the parent with the higher AGI if the time was equal.13Internal Revenue Service. Other EITC Issues
Run the numbers separately. The EITC income limits for Single and Head of Household filers are lower than the combined limit for a married couple filing jointly. Two domestic partners with moderate incomes might each qualify individually, or one might be pushed past the cutoff by their own earnings alone.