Key differences between cohabitation and pre-nuptial agreements.

By Sondra I. Harris, Family Lawyer

When writing a cohabitation agreement, most attorneys look to a pre-nuptial agreement as a model, since, even today, pre-nuptial agreements are far more common than cohabitation agreements. While it is true that there are many similarities between these two, it is also true that there are differences that could be fatal to the unwary practitioner.

For example, an area which is almost considered boilerplate, or a “no-brainer‚” is the consideration clause of the agreement. In a pre-nuptial agreement, the consideration of the marriage itself, which is usually stated in the introductory paragraphs of the agreement. In a cohabitation agreement, however, there is no marriage. Indeed, the parties state that this is not to be construed as an agreement to marry. Thus, other consideration must be listed and the attorney must be careful to include consideration that is legal in his or her jurisdiction. Thus, consortium, love or affection is probably not sufficient consideration in any jurisdiction, and specific consideration should be listed.

Another example of where cohabitation agreements differ from pre-nuptial agreements is when considering children. There is, in every state, a presumption of legitimacy of children born in a marriage. The same is not true in cohabitation relationships. Thus, it is possible that a couple might live together for many years, have children together, and then, if the child is not the child of the partner, have the right to take that child away forever. One way to avoid this is to have the parties agree to have genetic testing at the time of the birth of the child. If they agree to that (usually with a joke or a nervous laugh) they cannot then refuse at a later date when the question is far more important. If the child is not the child of the partner, the relationship may break up, or, the partner might then choose to adopt the child, thus solving problems in the future.

Perhaps, more importantly, is the issue of children with same-sex couples. If the parties are planning to have children either through artificial insemination, or through adoption (adoption by same-sex couples is permitted in every state but Florida), it is important to spell that out in the agreement and make sure that both parties have equal rights to custody and support of the child through adoption. (lt is interesting to note that recently in New Jersey, the court has held that the psychological parties of the child has visitation and custody rights similar to that of a biological parent).

A final example of the difference between pre-nuptial agreements and cohabitation agreements is what happens upon the illness of a party. While all persons, married or not, should have living wills and health care proxies, it is critical that these be done for co-habitants. While a spouse is considered to have the right to make health care decisions for another spouse, a co-habitant will only be consulted if there is no other relative available. Indeed, it is not unknown for co-habitants to be excluded from a partner’s hospital room by the patient’s family and for that family to make decisions that are different from what the person truly wanted. Health care proxies give a partner the right not only to make “do not resuscitate” orders, but also to make decisions about extraordinary measures, or give nutrition and hydration. It is also possible to allow a partner to make a decision as to donating organs, if the worst happens, and a partner passes away.

Thus, it is clear that when drafting a cohabitation agreement, an attorney must be careful to take into consideration the special needs of unmarried partners, and not to treat these agreements as simply modifications of pre-nuptial agreements.


Sondra I. Harris is a managing partner in charge of the Matrimonial Section of the Sondra I. Harris & Associates law firm in Rockville Center, NY. She has served as the Chair of the Cohabitation Committee of the ABA since 1992 and has contributed articles to publications such as the Family Advocate and the American Journal of Family Law.