Missouri Doesn’t Recognize Common-Law Marriage: Why Unmarried Couples Need an Estate Plan

Missouri has not recognized new common-law marriages since 1921. No matter how many years you have lived together, shared finances, or raised children with a partner, Missouri law treats you as legal strangers unless you are formally married, with no automatic inheritance rights, no default medical decision-making authority, and no spousal protections if something happens.

Here is what that actually means for unmarried couples in Missouri, and how an estate plan closes the gap.

Does Missouri Recognize Common-Law Marriage?

No. Missouri abolished common-law marriage in 1921, and no length of cohabitation, no matter how long-term or committed, creates a legally recognized marriage in the state. Couples who have lived together for decades have no more automatic legal rights toward each other than roommates, unless they hold a valid marriage license.

Missouri does recognize a common-law marriage that was validly formed in a different state before that state also abolished the practice, but this exception rarely applies to couples currently living together in Missouri without ever having married anywhere.

What Happens to an Unmarried Partner If There Is No Will?

Under Missouri’s intestate succession law (RSMo § 474.010), an unmarried partner inherits nothing automatically, no matter how long the relationship or how intertwined your finances were. The law only recognizes spouses, children, and other blood or legally adoptive relatives, a domestic partner has no legal standing in the probate process at all.

This means a surviving partner could be left with no legal claim to a jointly used home, shared vehicle, or personal belongings that were never formally retitled in both names, even after decades together.

Can an Unmarried Partner Make Medical Decisions in a Hospital?

Not automatically. Missouri hospitals generally follow a legal hierarchy of family members for medical decisions when a patient cannot communicate, and an unmarried partner typically has no place in that hierarchy, regardless of how long the relationship has lasted or how well the partner knows the patient’s wishes.

A healthcare power of attorney is the only way to guarantee your partner has the legal authority to make medical decisions on your behalf, and to be present for those conversations with hospital staff at all.

What Documents Do Unmarried Couples in Missouri Actually Need?

A complete plan for an unmarried couple typically needs to accomplish everything marriage would otherwise provide automatically:

• A will or trust naming your partner as a beneficiary, without one, they inherit nothing under Missouri intestacy law
• A healthcare power of attorney naming your partner as your medical decision-maker
• A durable power of attorney for finances, so your partner can manage bills and accounts if you are incapacitated
• Updated beneficiary designations on retirement accounts and life insurance, which pass outside a will entirely
• A beneficiary deed or joint titling review for real estate you share, to avoid probate and clarify ownership

Every one of these documents is optional for married couples in the sense that state law provides a default that usually favors the surviving spouse. For unmarried couples, none of these defaults exist, each document has to be affirmatively put in place.

What About Children From an Unmarried Relationship?

A child’s inheritance rights from each biological or legally adoptive parent are generally unaffected by whether the parents were married to each other, but this does not solve the guardianship and inheritance-structuring issues every parent needs to address. Unmarried parents still need to name a guardian for minor children and decide how any inheritance is managed until they reach adulthood, exactly as married parents do.

Unmarried parents should not assume that a child’s rights toward one parent automatically extend to that parent’s unmarried partner in a blended household, a stepparent-equivalent role with no legal marriage typically has no inheritance rights toward the children at all unless specifically included in a will or trust.

Working With a Missouri Attorney as an Unmarried Couple

Because Missouri law provides none of the automatic protections married couples rely on, an estate plan is not optional for unmarried partners who want their relationship legally recognized in a crisis or after death. An attorney at Mid-America Law Practice can build a complete set of documents, will or trust, powers of attorney, and beneficiary planning, that gives your partner the legal standing state law does not.

General information on Missouri intestate succession law is available through the Missouri Judiciary website.

Frequently Asked Questions: Estate Planning for Unmarried Couples in Missouri

1. Does living together for many years create a common-law marriage in Missouri?

No. Missouri abolished common-law marriage in 1921. No length of cohabitation creates legal marriage rights in the state.

2. Does my unmarried partner inherit anything if I die without a will?

No. Missouri intestate succession law only recognizes spouses and blood or legally adoptive relatives. An unmarried partner has no automatic inheritance rights.

3. Can my partner make medical decisions for me without a healthcare power of attorney?

Generally not. Missouri hospitals follow a legal hierarchy of family members that typically does not include an unmarried partner.

4. What happens to our shared home if only one of us is on the title?

The non-titled partner may have no legal claim to the property if the titled partner dies without a will or trust naming them as a beneficiary.

5. Do our children automatically have rights to inherit from my partner even though we’re not married?

A child’s inheritance rights depend on legal parentage, not the parents’ marital status to each other, but a partner’s own children from a prior relationship generally have no automatic rights toward a non-biological, non-adoptive stepparent-equivalent partner.

6. What is the single most important document for an unmarried couple?

There is no single document, a complete plan generally requires a will or trust, a healthcare power of attorney, and a durable financial power of attorney, since none of these are provided automatically as they are for married couples.

About the attorney

Azra Ahmad, Founder & Managing Attorney

Azra focuses on estate planning, elder law, personal injury and traffic law for families across the St. Louis area. She earned her JD from Saint Louis University School of Law, is licensed in Missouri and Illinois, and is a member of The Missouri Bar, WealthCounsel and ElderCounsel. Before law, she worked as a speech-language pathologist with children and seniors.

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