Cohabitation Agreement

A Cohabitation Agreement in the United States sets out the rights, duties and consideration binding the parties to it.

The legal foundation for cohabitation agreements in the United States was established by the California Supreme Court in Marvin v. Marvin (1976) 18 Cal.3d 660, which held that express contracts between nonmarital partners concerning property rights are enforceable unless the agreement is explicitly founded on sexual services as consideration. The Marvin decision recognized that unmarried couples who share their lives and accumulate property together may reasonably create enforceable agreements regarding their respective property rights, and that public policy does not prohibit enforcement of such agreements. Courts in New York, New Jersey, Washington, Oregon, Minnesota, and the majority of US jurisdictions have followed the Marvin framework, treating cohabitation agreements as standard contracts subject to the Restatement (Second) of Contracts and the Uniform Commercial Code where applicable.

Unmarried cohabitation in the United States has increased substantially, with the US Census Bureau's Current Population Survey reporting approximately 8.3 million unmarried partner households as of 2023. Unlike married couples, cohabiting partners have no automatic statutory rights to each other's property, retirement benefits, or survivorship interests upon separation or death in the vast majority of states. A Cohabitation Agreement fills this legal gap by creating contractual rights that substitute for the statutory protections available to married spouses under state equitable distribution statutes (applicable in 41 states) or community property statutes (applicable in Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, and Wisconsin).

The enforceability of cohabitation agreements varies by state, with a small number of jurisdictions imposing additional requirements. Illinois, under the Illinois Domestic Violence Act of 1986 and related case law, historically required cohabitation agreements to be in writing and has applied heightened scrutiny to agreements between unmarried partners. Minnesota courts under Palmen v. Palmen (1979) have upheld cohabitation agreements where the agreement is supported by adequate consideration independent of the cohabitation relationship. Courts in all jurisdictions examine whether the agreement was entered into voluntarily, whether both parties made adequate financial disclosure, and whether the terms are not unconscionable — applying the same standards used for prenuptial agreement review under the Uniform Premarital Agreement Act (UPAA), Section 6.

A Cohabitation Agreement differs from a Domestic Partnership Agreement, a Prenuptial Agreement, and a Roommate Agreement in scope and legal effect. A Domestic Partnership Agreement may confer specific statutory benefits in states or municipalities that recognize registered domestic partnerships, such as California under Family Code Section 297 or the District of Columbia. A Prenuptial Agreement requires a future or existing marriage to become effective and is governed by the UPAA or the Uniform Premarital and Marital Agreements Act (UPMAA). A Roommate Agreement addresses shared living expenses and household duties between unrelated individuals without addressing the broader property ownership and financial integration provisions found in a Cohabitation Agreement for intimate partners.

A Cohabitation Agreement in the United States is needed whenever two unmarried partners share a residence and wish to establish legally enforceable terms governing their property rights, financial obligations, and the consequences of separation.

Unmarried couples purchasing real property together face significant legal exposure without a written agreement specifying each partner's ownership percentage, contribution to the down payment and mortgage payments, and rights upon sale or separation. Real property purchased by unmarried partners is typically held as tenants in common or joint tenants with right of survivorship, and the form of title alone does not resolve disputes about unequal contributions. The Washington Supreme Court addressed this scenario in Connell v. Francisco (1995) 127 Wash.2d 339, recognizing equitable claims between cohabiting partners but emphasizing the difficulty and expense of litigation without a written agreement.

Partners who combine household finances — sharing bank accounts, credit cards, or monthly expenses such as rent, utilities, insurance, and groceries — need a Cohabitation Agreement specifying how shared expenses are divided, which debts remain the individual responsibility of each partner, and how joint accounts are handled upon separation. Without written terms, a partner who contributed disproportionately to shared expenses has no contractual basis for reimbursement and must rely on equitable claims such as unjust enrichment, which courts apply inconsistently across jurisdictions.

Cohabiting partners where one partner owns a business face particular risk without a written agreement. Business assets acquired or grown during cohabitation may become the subject of property claims by the non-owning partner, particularly in states that recognize implied partnership or constructive trust theories. A Cohabitation Agreement that expressly addresses business ownership — specifying that the business remains the separate property of the owning partner — prevents costly litigation over business valuation and division.

Partners relocating to a common law marriage state — including Colorado, Texas, Iowa, Kansas, Montana, Oklahoma, South Carolina, and Utah — need a Cohabitation Agreement with an explicit statement that the partners do not intend to create a common law marriage, which courts in Texas under Family Code Section 2.401 and Colorado under Revised Statutes Section 14-2-109.5 will consider as evidence of intent.

Same-sex and opposite-sex couples who choose to cohabit rather than marry for personal, financial, or tax reasons benefit from a Cohabitation Agreement that creates contractual rights equivalent to certain marital protections — particularly regarding property division, health care decision-making authority through a linked Health Care Proxy, and beneficiary designations — without triggering the tax and benefit implications of legal marriage under the Internal Revenue Code.

A Cohabitation Agreement for unmarried partners in the United States must address the full scope of the couple's financial and property arrangements to provide enforceable protections equivalent to the statutory framework available to married spouses.

The identification of parties clause names both partners with their full legal names, current addresses, dates of birth, and the date the cohabitation began. Accurate party identification is a basic contract formation requirement under the Restatement (Second) of Contracts, Section 9, and prevents disputes about the identity of the contracting parties.

The property ownership clause is the core provision of a Cohabitation Agreement, specifying which assets are the separate property of each partner (property owned before cohabitation or acquired by gift or inheritance during cohabitation) and which assets are jointly owned (property acquired together during the relationship). For real property, the agreement should specify the ownership percentage, each partner's contribution to the purchase price and mortgage payments, and whether the property is held as tenants in common or joint tenants with right of survivorship. The distinction matters because joint tenancy includes an automatic right of survivorship upon death, while tenancy in common does not.

The financial responsibilities clause addresses how the partners share living expenses — rent or mortgage payments, utilities, groceries, insurance premiums, property taxes, and maintenance costs. The agreement should specify whether expenses are split equally, proportionally based on income, or allocated by category (e.g., one partner pays the mortgage while the other pays utilities and groceries). The forms-legal.com Cohabitation Agreement template includes a 7-section questionnaire that guides partners through each of these financial allocation decisions.

The debt allocation clause specifies that debts incurred by one partner before or during the cohabitation remain the sole obligation of the incurring partner, unless both partners expressly agree to joint liability. Under general creditor law in all US states, one unmarried partner is not automatically liable for the other partner's debts — unlike certain marital obligations under the doctrine of necessaries recognized in some states. The agreement should address how jointly incurred debts (such as a joint credit card or co-signed loan) are allocated upon separation.

The separation provisions clause establishes the process for dividing property and unwinding financial arrangements if the relationship ends. The agreement should specify a notice period, the process for valuing and dividing jointly owned property (including whether the couple will use mediation or appraisal), the timeline for one partner to vacate a shared residence, and how ongoing financial obligations (such as a shared lease or mortgage) are handled during the transition period.

The dispute resolution clause specifies whether disagreements about the agreement are resolved through mediation, binding arbitration under the Federal Arbitration Act (9 U.S.C. Section 1 et seq.) and applicable state arbitration statutes, or litigation in state court. Mediation and arbitration provisions reduce legal costs and preserve the privacy of the parties' financial arrangements.

The estate planning integration clause addresses how the Cohabitation Agreement interacts with each partner's will, trust, beneficiary designations, and health care directives. Unmarried partners have no automatic inheritance rights under any US state's intestacy statutes — a surviving unmarried partner receives nothing from a deceased partner's estate unless the partner is named in a will, trust, or beneficiary designation. The agreement should require each partner to maintain estate planning documents consistent with the property rights established in the Cohabitation Agreement.

The amendment and termination clause specifies that the agreement may be modified only by written amendment signed by both partners, and that the agreement terminates upon the partners' marriage (at which point a Prenuptial Agreement under the UPAA should replace the Cohabitation Agreement), mutual written agreement to terminate, or permanent separation as defined in the agreement.