Today, the Brady Bunch family is more common than Ward and June Cleaver of Leave It To Beaver. Couples come together with children from prior relationships and may, or may, not have additional children together. This creates planning issues not present for the old-style nuclear family. Top of the list: making your spouse your primary beneficiary yet providing for children you may have from a prior relationship. The concern here is that, as the surviving spouse is not the biologic parent of all children the couple are raising, not all children will be treated equally by the surviving spouse in his or her will.
The easiest way to discuss the problem is through an example. Tom and Betty married in 1999. Tom has a son Tom, Jr. from a prior relationship and Betty already had a daughter Betsy when she married Tom. Together, Tom and Betty are the parents of Prince, a son born in 2002. Tom and Betty each have 401(k) and brokerage accounts. They also own a house together and have very little else in the way of other assets. First point, Tom and Betty should check the beneficiary designations on their 401(k) and brokerage accounts to make sure a prior spouse is no longer named as beneficiary. Second, how does Tom provide for Tom, Jr. or Betty for little Betsy while still making their current spouse the primary beneficiary? In my mind, the first issue is the size of the pie. If the couple owns limited assets with modest current earnings they are just getting by on (the majority of Americans are in this boat), then there may not be much to be done for junior in one's last will. If there is some cushion, the easiest route is purchasing a modest life insurance policy naming junior from the prior relationship as beneficiary while making the new spouse sole heir under your will. The proceeds of the life insurance policy pass outside of probate to junior while the new spouse is the sole beneficiary of all other assets.
Rather than a couple of average means, let's assume Tom and Betty have some assets / savings set aside. In these circumstances, a revocable trust is the preferred estate planning vehicle. Why? It is more expense on the front end in attorney fees for estate planning but a revocable trust (sometimes called a living will) offers more flexibility and control over distribution of the assets after the death of the first and/or second spouse.
The following are links to additional articles on the subject: