When you are entering into a marriage with considerable assets and/or children from a previous marriage or marriages, the reasons why you may want to enter into a premarital agreement are clear. There is sometimes a stigma attached, but the notion that a prenuptial agreement is a romance killing instance of bet hedging can only logically proceed if you think that all marriages are of the storybook variety. The fact is that upwards of half of the marriages that take place in the United States each year involve people who are getting remarried, and this changes the paradigm and the underlying anatomy of the thing called marriage.
Premarital agreements are commonly entered into with estate planning in mind, in many cases for the primary purpose of protecting the interests of children from a previous marriage or marriages. This may suffice permanently in some cases, but then again it may not. If a couple who had entered into a prenuptial agreement prior to marrying stayed in the union for many years after that it may not be adequate at some point, and a post-nuptial agreement may be in order. This need not be due to a contentious perspective; a post-nuptial agreement may be something that both parties see as necessary and appropriate.
There are other cases when a post-nuptial agreement can be very useful for married couples who have been together all along having never divorced and with no prenuptial agreement in place. The most common reason why husbands and wives argue is due to disagreements about money, and of course this leads to many divorces. Even a couple who have been married a long time can feel very passionately about estate plans and it can put a strain on the marriage. A good way to settle these differences is to enter into a post-nuptial agreement that defines personal property so that each person can bequeath their share of the assets as he or she sees fit.