By using a dual Trust, you can protect more of your estate. Your estate can be set up in a Trust to give your children or grandchildren up to the maximum that can be passed tax-free to the next generation--currently $2,000,000. The balance can be given to the surviving spouse under the unlimited marital deduction rules. Your spouse then may also pass the maximum $2,000,000 to the next generation tax-free. By doing so, you have increased the tax-free pass-through to $4,000,000. The surviving spouse can get the income from the Trust with the principal eventually passing to the children.