You have worked hard all your life. You love your heirs and want to provide for them after your death. You have good intentions. Yet most Americans make critical mistakes in their estate planning that eviscerate their wealth and leave their heirs scrambling to figure out what went wrong.

Here are the biggest estate-planning mistakes you can make:

1. Not having a will. This is the big one. If you don’t have a will, much of your estate will enrich creditors, lawyers, and Uncle Sam. If there is anything left, it could be distributed to people you never intended to receive it. If you do nothing else, don’t ignore this advice: Prepare and execute a will immediately!

2. Not taking steps to avoid probate. All most people know about probate is that it’s something to be avoided. They’re right. The process can be arduous, lengthy, and expensive. A competent trusts and estates attorney can help you avoid probate by creating a living trust. A living trust permits you to sidestep probate court for all assets in the trust, which can include your home.

You should also ask your estate-planning attorney about an irrevocable trust. Once you transfer property to an irrevocable trust, you lose all your rights of ownership and control (unlike a living trust, where you retain control). Irrevocable trusts can be powerful tools to avoid estate taxes. Assets in these trusts are generally immune from both estate and income tax, as long as you do not receive any benefit.

3. Not naming a beneficiary for retirement accounts. You can easily avoid probate for your retirement accounts. All you have to do is name one or more beneficiaries (which could be your living trust) on the accounts. Upon your death, these accounts will pass directly to your designated beneficiaries. Just be sure to keep your beneficiaries current—otherwise, your ex-wife could be in for a windfall!

4. Not establishing payable-on-death accounts. Cash accounts will pass directly to whoever is designated in a “payable on death” form, without going through probate. Ask your bank, credit union, or savings and loan association to provide you with the correct form.

5. Not establishing transfer-on-death registrations. Taxable stocks, bonds, and brokerage accounts can be transferred without probate. You need to register your taxable accounts in what’s called a “beneficiary form.” Your financial institution can provide you with the correct form. The beneficiary has no right to the account until your death.

6. Not having a prenuptial agreement. I know it’s not romantic, but you should have a prenuptial agreement, particularly if you have remarried later in life. A prenup can limit or waive one party’s right to a statutory share of each estate. If you don’t have a prenup in place, upon your death state law may give your spouse certain rights in your assets, regardless of how they are titled and regardless of your intentions. Because prenups have serious legal ramifications, both spouses should have separate, independent legal representation-this is not a DIY project. Keep the original with your estate-planning documents.

Dan Solin is a Senior Vice-President of Index Funds Advisors. He is the author of the New York Times best sellers The Smartest Investment Book You’ll Ever Read, The Smartest 401(k) Book You’ll Ever Read, and The Smartest Retirement Book You’ll Ever Read. . His latest book is Timeless Investment Advice.

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