It is likely that you and your spouse each have an IRA. It is also likely that you have named one another as the primary beneficiary upon death. Thereafter, you likely have named your child as the contingent beneficiary on your respective IRAs.
The USA Today’s article, “Tips on the best way to pass your IRA down to your child,” advises that when your child inherits the IRAs, the best way for him or her to avoid taxes and let the accounts grow is to name your child as your "contingent beneficiary" (to inherit the IRA if the other spouse does not survive you). In that way, your child will be able to hold that account as an "inherited” IRA.
Your child is entitled, under the current law, to withdraw the money gradually over his or her life expectancy. Although he or she must withdraw a certain amount each year (a required minimum distribution or RMD) and pay taxes on that amount, the RMDs are usually small, especially in the early years.
The account might last until your child reaches his or her mid-80s by taking advantage of the "life expectancy" or "stretch" payout.
However, there's nothing to prevent your child from withdrawing more than the RMD—or even cashing out the whole account right after you pass away.
In order to prevent this, you'd have to use a much more complicated strategy and the help of an estate planning attorney. You could place your money in a “trusteed IRA” or leave the IRA to a “see-through trust” for your child's benefit.
Here is one other piece of bad news: the U.S. Congress is currently considering legislation that would force a five-year payout for inherited IRAs over $450,000.
Reference: USA Today (November 10, 2016) “Tips on the best way to pass your IRA down to your child”