The Indiana Uniform Premarital Agreements Act states that a prenuptial agreement is "an agreement between prospective spouses that is executed in contemplation of marriage and becomes effective upon marriage," according to Indiana Code 31-11-3-1. A prenuptial agreement is good for the life of the marriage only, although the spouses may change the agreement during their marriage. Prenuptial agreements may only cover certain topics, usually relating to property.
The spouse of a deceased person has a right either to take the share of the couple's property granted to her in the deceased person's will, or to take an elective share, according to Indiana Code 29-1-3-1. The elective share is set by Indiana law, and amounts to up to half of the remaining estate after the deceased person's debts are paid, according to Indiana Code 29-1-3-1. However, the spouse may waive her right to any share of the deceased person's estate.
Indiana Code 31-11-3-5 permits a couple to set rules for their respective wills in a prenuptial agreement. If the spouses agree in their prenuptial agreement that one spouse or the other will give up his right to the property if the other spouse dies, and the spouses are still married when the second spouse dies, the waiver in the prenuptial agreement will supersede both the will, if it grants a share to the spouse, and the elective share created by Indiana law, according to Indiana Code 29-1-3-5.
Spouses may only create a prenuptial agreement that affects how each of the two will inherit if the other spouse dies, according to Indiana Code 31-11-3-5(b). It cannot affect the rights of a child of either or both spouses to child support or her elective share. Also, a prenuptial agreement will be ignored if following its rules will leave the surviving spouse in undue financial hardship, according to Indiana Code 31-11-3-8. In that case, the court will either grant the share of the estate left to the surviving spouse in the will or allow the surviving spouse to take an elective share, according to Indiana code 29-1-3.