Most people aren’t aware that their wills don’t have the final say concerning assets held in retirement accounts such as 401(k) plans and individual retirement accounts (IRAs). The beneficiary provisions of these retirement accounts supersede those of wills.

Forgetting to update estate planning documentation following a divorce, or death of the beneficiary or even remarriage is one of the most common mistakes people make when it comes to retirement accounts.

Your beneficiary forms should be reviewed and updated after every major life event (i.e. marriage, divorce, birth or death).

If you get remarried and change your will, but forget to amend your IRA or 401(k), the person named on your IRA or 401(k) beneficiary form (most likely your ex) would be legally entitled to your assets when you die. For those who are divorced, this problem could result in a posthumous nightmare: Your ex-spouse might get your IRA and/or 401(k) assets.

After your death, your IRA and 401(k) assets go to whomever you designate as the beneficiary when you set up those accounts, unless you’ve since filed updated beneficiary forms. If your life situation has changed in the years since you set up those accounts, there may be a conflict with your will, especially if the will was drawn up more recently. You may now be divorced and remarried. You may have had no children when you set up the account and now have grown children who you want designate as beneficiaries

Rules governing 401(k) plans require that account assets automatically go to the person who is your spouse when you die – unless you get your spouse to relinquish his or her claim to the assets and file the required paperwork with your employer demonstrating this and designating your intended beneficiaries. (A copy of a prenuptial agreement won’t do it; you must file the spouse’s sign-off that they are giving up any claim to the assets.) Failing to attend to these issues could result in unintended outcomes.

Another common mistake is either failing to name a beneficiary to your retirement accounts or naming your estate as beneficiary to your retirement account. By not naming an individual as an IRA or 401(k) beneficiary, the probate court would consider those assets to be part of your estate after you die, and thus it would be subject to creditors’ claims.

Without a named individual as a beneficiary, an IRA or 401(k) would also not be distributable to your heirs until the probate process concludes, which can take more than a year. Do your family a favor and be sure you have named an actual person as your beneficiary, not your estate.