The practical difference between marriage and domestic partnership comes down to federal recognition. Marriage is recognized by the federal government, every state, and most foreign countries. A domestic partnership exists only in roughly a dozen U.S. jurisdictions and carries no weight under federal law. That single gap drives nearly every real-world consequence that follows: taxes, Social Security, immigration, workplace leave, health coverage, inheritance, and whether your relationship still exists after you cross a state line.
Federal Tax, Social Security, and Immigration
Married couples can file a joint federal income tax return under 26 U.S.C. § 6013, which often lowers the combined bill.1Office of the Law Revision Counsel. 26 U.S. Code 6013 – Joint Returns of Income Tax by Husband and Wife Domestic partners cannot file jointly federally no matter how their state classifies the relationship. Each partner files as single, or as head of household if they qualify.
Marriage also opens two large wealth-transfer benefits. Spouses can move unlimited property between each other during their lifetimes without triggering federal gift tax.2Office of the Law Revision Counsel. 26 U.S. Code 2523 – Gift to Spouse When a spouse dies, the estate tax marital deduction lets the entire estate pass to the survivor free of federal estate tax.3Office of the Law Revision Counsel. 26 USC 2056 – Bequests, Etc., to Surviving Spouse Neither applies to domestic partners, so large transfers between partners can generate a tax bill that married couples never see.
Social Security works the same way. A married person can collect spousal retirement benefits worth up to half of their spouse’s benefit, even without their own work history, and a surviving spouse can draw survivor benefits based on the deceased spouse’s record.4Office of the Law Revision Counsel. 42 USC 402 – Old-Age and Survivors Insurance Benefit Payments Domestic partners get neither, because the Social Security Administration uses the federal definition of marriage.
Immigration follows the federal pattern. USCIS does not treat a domestic partnership as a basis to sponsor a partner for a visa or green card, and specifically lists domestic partnerships among relationships it does not consider marriages for immigration purposes.5U.S. Citizenship and Immigration Services. Chapter 6 – Spouses A U.S. citizen can petition for a spouse. A domestic partner cannot.
Workplace Leave, Health Coverage, and Hidden Taxes
Federal employment law consistently treats “spouse” and “domestic partner” as separate categories, and this is where the gap tends to surprise people.
FMLA Leave
The Family and Medical Leave Act lets eligible employees take up to 12 weeks of unpaid, job-protected leave to care for a spouse with a serious health condition. The Department of Labor has confirmed the statutory definition of “spouse” was written to exclude domestic partners.6Federal Register. Definition of Spouse Under the Family and Medical Leave Act If your domestic partner becomes seriously ill, federal law does not guarantee you leave to care for them. Some states have their own family leave laws that reach domestic partners; federal FMLA does not.
COBRA Continuation Coverage
When a worker loses group health insurance through a qualifying event, COBRA lets certain “qualified beneficiaries” continue coverage at their own expense. The statute lists the employee, their spouse, and their dependent children.7Office of the Law Revision Counsel. 29 U.S. Code 1167 – Definitions and Special Rules Domestic partners are not on that list. If you are covered under your partner’s plan and they lose their job, you have no independent federal right to COBRA.
Imputed Income on Partner Health Benefits
When an employer pays for a spouse’s health insurance, the coverage is tax-free. When an employer pays for a domestic partner’s coverage, the fair market value usually gets added to the employee’s taxable income as imputed income, unless the partner qualifies as a tax dependent under IRC § 152.8U.S. Office of Personnel Management. Insurance Benefits The employee then pays income and payroll tax on that amount, which can add hundreds or thousands of dollars a year. Many people only notice when they see the first paycheck after adding a partner to the plan.
Federal Employee Health Coverage
Federal workers face an added limit: domestic partners are not eligible family members under the Federal Employees Health Benefits program, so a federal employee cannot add a domestic partner to their FEHB plan.8U.S. Office of Personnel Management. Insurance Benefits No federal law requires private employers to offer partner coverage either, though many do voluntarily and some states require it for fully insured plans.
Hospital Visitation and Medical Decisions
Hospital visitation is one area where domestic partners are protected federally. Any hospital participating in Medicare or Medicaid must let patients designate their own visitors, including a domestic partner, and cannot restrict visitation based on sexual orientation.9eCFR. 42 CFR 482.13 – Condition of Participation: Patient’s Rights You will not be turned away at the door because you are not married.
Medical decision-making is different. A spouse generally has automatic legal authority to make healthcare decisions for an incapacitated partner. A domestic partner may have similar default authority in a state that recognizes the partnership, but in a state that does not, you can be treated as a legal stranger with no voice in your partner’s care. The reliable fix is a signed healthcare power of attorney, which grants decision-making authority regardless of how a state views your relationship.
What Happens When You Move
Marriage travels. The Full Faith and Credit Clause (Article IV, Section 1) generally requires states to respect legal acts performed in other states, and the Respect for Marriage Act of 2022 requires states and the federal government to recognize any marriage that was valid where it was performed. Married in one state, married in all 50.
Domestic partnerships have no equivalent protection. Only about seven states and the District of Columbia currently offer domestic partnership registration, and no federal law obligates other states to honor those relationships. Register in one state and move to a state without a similar law, and your legal status may simply disappear, along with the rights that came with it. For couples who have both options, this is one of the strongest practical arguments for choosing marriage.
Children and Parentage
When a child is born during a marriage, the non-biological spouse is generally presumed to be the child’s legal parent. No extra legal steps are needed for both spouses to appear on the birth certificate and exercise full parental rights.
Domestic partners get a less consistent answer. A few states that recognize domestic partnerships extend the parentage presumption to registered partners, but many do not. Where it does not apply, the non-biological partner usually has to pursue a second-parent adoption or a court parentage judgment to establish legal rights. Without that order, the non-biological partner can be shut out of custody decisions if the relationship ends or if the family moves to a state that does not recognize the partnership.
Even where the presumption applies, an adoption or court parentage judgment is still worth getting. Court orders travel across state lines far more reliably than domestic partnership status does, and the protection matters most when something goes wrong.
Inheritance When a Partner Dies
If a married person dies without a will, every state’s intestacy laws guarantee the surviving spouse a share of the estate. The share varies, but the spouse is always near the front of the line. On top of that, the federal estate tax marital deduction lets the entire estate pass to the surviving spouse tax-free.3Office of the Law Revision Counsel. 26 USC 2056 – Bequests, Etc., to Surviving Spouse
A surviving domestic partner usually has no such safety net. Under the intestacy laws of most states, a domestic partner is a legal stranger, so the deceased partner’s assets pass to blood relatives rather than the survivor. A handful of states have changed this for registered partnerships, but the default rule across the country leaves a surviving partner with nothing when their partner dies without a will or trust.
The financial consequences can be severe. A partner who shared a household for decades can inherit nothing while distant relatives collect everything. The reliable protection is active estate planning: a will or revocable living trust naming the partner as beneficiary, up-to-date beneficiary designations on retirement accounts and life insurance, and transfer-on-death deeds for real property where state law allows them. For married couples these documents are useful. For domestic partners they are essential.
How You Enter Each Status
Marriage requires a license from a county clerk or register of deeds. Both partners typically appear in person with government-issued ID, provide basic personal information, and pay a fee that generally runs between $20 and $125 depending on the location. The couple then holds a ceremony performed by someone legally authorized to officiate, and the completed certificate is filed with the county.
Registering a domestic partnership is largely a paperwork step. In states that offer it, couples file a declaration with a secretary of state or local registrar, listing names, addresses, and an affirmation that they share a committed domestic life. Fees typically run from $10 to $80. No ceremony is required. Some jurisdictions impose extra requirements such as a shared residence or joint responsibility for basic living expenses.
Both statuses require the parties to be at least 18 (without parental or judicial consent in most places), legally competent, and not closely related by blood. Neither is available if either person is already married or already in a registered domestic partnership with someone else.
How You End Each Status
Ending a marriage means filing for divorce in court. One spouse files a petition and formally serves the other, a judge oversees the division of assets and debts, and if there are children the court addresses custody and support. Filing fees generally run from $50 to $450, and the case ends only when a judge signs a final judgment. Attorney fees, mediation, and service costs can push the total far above the filing fee.
Ending a domestic partnership can be simpler. Several states let partners file a notice of termination with the office where they registered, bypassing court entirely. That path is usually faster and cheaper, but it is typically available only when there are no contested assets, no children, and the partnership was short. When those conditions aren’t met, dissolving a domestic partnership looks much like a divorce: one partner petitions the court, and a judge divides property and may order partner support.
One tax wrinkle is worth flagging. Alimony paid to a former spouse follows specific federal tax rules, but support between former domestic partners may not be treated the same way because the IRS does not recognize the underlying relationship. Raise this with a tax professional before agreeing to any support arrangement.