Prenuptial agreements can address property acquired before a marriage, such as a home or Grandpop's antique desk, although some states recognize each spouse's rights to his or her premarital property anyway, according to attorney Brian Liu, chairman and co-founder of LegalZoom.com, an online law center.
"The problem people have is, after they get married, what's become yours has become co-mingled," Liu says. "People can't trace after 10 years of marriage what was theirs and what's joint property."
Other areas prenups can cover are the waiving of spousal support and death benefits.
"Even if you make a will and exclude your spouse, some courts will look unfavorably on that," Liu says. "If you have a prenuptial agreement, you can say, 'That was my intention to cut out the spouse.'"