The legal rights of a cohabitee — someone living with a romantic partner without being married or in a civil partnership — are far narrower than most people assume. U.S. law gives unmarried partners no automatic claim to each other’s property, income, inheritance, Social Security, or medical decisions. Whatever protection you want, you generally have to create yourself through contracts, estate planning documents, and how you title what you own.
Living Together Does Not Make You Married
The idea that enough years under the same roof turns a couple into “common law” spouses is mostly a myth. Only about ten states and the District of Columbia still allow new common law marriages to form, among them Colorado, Iowa, Kansas, Montana, South Carolina, Texas, and Utah. New Hampshire recognizes cohabitation as marriage only after one partner dies, and Rhode Island and Oklahoma recognize it through court decisions rather than statute.1National Conference of State Legislatures. Common Law Marriage by State In every other state, no amount of time together creates a legal marriage.
That matters because marriage carries a built-in package of rights: property division on divorce, inheritance under intestacy, tax benefits, Social Security survivor payments, authority to make medical decisions. Cohabitees sit outside that package entirely. When something goes wrong, you fall back on contract law, trust law, and whatever paperwork you had the foresight to sign.
Property and the Home if You Separate
There is no court that divides a cohabiting couple’s assets by fairness or need. Property belongs to whoever holds legal title. If only one partner’s name is on the deed, the other partner has no automatic claim to the home, no matter how many years they lived there or how much they paid toward the mortgage, taxes, or repairs.
A partner left off the title can sometimes recover an interest through a resulting trust (where they contributed to the purchase price) or a constructive trust (where both partners shared an understanding of joint ownership and one relied on it financially). Both claims demand strong documentary evidence — bank records, receipts, written communications. Verbal promises rarely carry the day.
If you want the home to pass automatically to your partner, how the deed is titled is decisive. Owning as “joint tenants with right of survivorship” means the surviving partner takes the deceased partner’s share automatically, outside probate. This has to be stated on the deed itself. The default in most states is “tenancy in common,” which sends each partner’s share through their estate and potentially to their relatives rather than to you.
Personal items and bank accounts follow the same logic. Things belong to whoever paid for them; joint account funds belong to both account holders. Keep records of significant purchases.
Support After a Breakup
Alimony is a feature of divorce, not of cohabitation. Courts generally have no authority to order one former cohabitee to support the other, even after decades together and even if one partner left the workforce to raise children or run the household.
“Palimony” exists in a handful of states but is unreliable. Where it is recognized, courts look for an explicit agreement, written or implied by conduct, that one partner would support the other. Some states enforce only written agreements. Many reject the claim entirely. Treating palimony as a safety net is a serious gamble.
The practical consequence is that a partner who steps back from paid work has no legal cushion if the relationship ends. Keeping separate savings and current professional skills is less a precaution than a necessity.
What Happens if Your Partner Dies
When a married person dies without a will, state intestacy laws send assets to the surviving spouse first. When an unmarried person dies without a will, those same laws send assets to blood relatives — children, parents, siblings. The surviving partner inherits nothing. The home can pass entirely to a relative the deceased barely knew.
A will is the single most important document for any cohabiting couple. It lets each partner leave assets to the other regardless of marital status. Without one, the surviving partner has no legal claim to the estate and few options to contest the result.
No Social Security Survivor Benefits
Social Security pays survivor benefits to a worker’s spouse, ex-spouse (if the marriage lasted at least ten years), children, and dependent parents. Unmarried partners are not on that list.2Social Security Administration. Survivors Benefits A cohabitee who spent decades relying on a partner’s income has no claim after that partner dies. For many couples this is the single largest financial consequence of not being married, worth potentially hundreds of thousands of dollars over a lifetime.
Estate and Gift Tax Gaps
Spouses can leave each other any amount of property at death with no federal estate tax, thanks to the unlimited marital deduction. The deduction is only available to a “surviving spouse.”3Office of the Law Revision Counsel. 26 USC 2056 – Bequests, Etc., to Surviving Spouse An unmarried partner does not qualify, so anything above the federal estate tax exemption — $15,000,000 per individual in 2026 — is taxed.4Internal Revenue Service. What’s New – Estate and Gift Tax Most couples will not hit that threshold, but for those with significant assets the exposure is real and plannable.
During life, spouses can give each other unlimited gifts tax-free. Unmarried partners are capped at the standard gift tax annual exclusion of $19,000 per recipient per year.5Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Transferring something substantial, like a half-interest in a home, can trigger gift tax if the value crosses that line.
Medical Emergencies and Decision-Making
If your partner is hospitalized and cannot communicate, you have no automatic authority to make medical decisions, read medical records, or guarantee visitation. Hospitals and courts default to the patient’s closest blood relatives. A parent or sibling who has been out of the picture for years may have more legal standing than the partner they share a home with.
The fix has to be in place before a crisis. A healthcare power of attorney (sometimes called a healthcare proxy) lets each partner name the other to make medical decisions during incapacitation. A separate financial power of attorney covers bank accounts, bills, and assets. Both must be signed while the person is healthy and competent — they are useless if signed after a medical emergency has already begun. State requirements vary, so working with an attorney is worth it. A living will can be added to spell out wishes on end-of-life care such as whether to continue life support.
Rights Involving Children
A child’s birth mother has automatic legal parental rights. An unmarried father’s rights depend on whether paternity has been legally established. In most states, signing a voluntary acknowledgment of paternity at the hospital or being listed on the birth certificate creates legal fatherhood. If paternity is disputed or never formally acknowledged, a court action with genetic testing may be needed.
Paternity is not a formality. Without it, an unmarried father may have no legal right to custody or visitation, and the child may have no right to the father’s inheritance, insurance benefits, or Social Security. Regardless of marital status, both biological parents owe child support, calculated under state guidelines based on income.
Second-Parent Adoption
If one partner is raising a child who is not biologically related to the other, the non-biological partner has no parental rights by default. Should the biological parent become incapacitated or die, the surviving partner can lose custody entirely. Second-parent adoption lets the non-biological partner become a legal parent without ending the biological parent’s rights. About half of states allow this for unmarried couples. In states that do not, the non-biological partner’s relationship to the child has no legal recognition at all.
Wrongful Death Claims
One boundary worth knowing: if your partner is killed by someone else’s negligence, you may have no standing to sue for wrongful death. Most states limit those claims to spouses, children, and parents. A few extend standing to registered domestic partners or common law spouses, but the majority exclude unmarried cohabitees.
The Documents That Close the Gap
Because the law supplies so little by default, unmarried couples who want legal security have to build it. A cohabitation agreement is a contract between partners that sets out how property, debts, and expenses are handled during the relationship and divided if it ends. These agreements are generally enforceable in U.S. courts if both parties sign voluntarily, both disclose their finances honestly, and the terms are not unconscionable.
A workable agreement addresses who owns what, how shared expenses are split, what happens to the home on separation, and how jointly acquired assets will be divided. Some couples also include a transition support provision.
Beyond that agreement, a full protective package usually includes:
- A will, directing assets to your partner instead of to blood relatives under intestacy.
- A healthcare power of attorney, authorizing your partner to make medical decisions if you cannot.
- A financial power of attorney, authorizing your partner to manage money matters if you cannot.
- Beneficiary designations on retirement accounts, life insurance, and bank accounts, which override a will for those specific assets.
- Property titled as joint tenants with right of survivorship, so the surviving partner inherits the home automatically.
Each document solves a different problem, and none substitutes for another. A will without a healthcare power of attorney still locks the surviving partner out of medical decisions. A cohabitation agreement without proper titling still sends the home through probate. The cost of putting these in place is modest next to what it costs to have none of them when a crisis arrives.