While Trusts are not needed to get the tax benefit, they are commonly used.  That is, you could leave the exemption amount directly to the children and the rest to your spouse.  But, Trusts can provide money management, ceditor protection, ongoing tax benefits and flexibility.  For Example, the credit shelter trust could pay all income to your spouse and your souuse could have the right to withdraw 5% of the principal per year, without causing that trust to be inlcude din the spouse’s estate. The Trustee could also have the discretion to use principal for your spouse’s health, education, maintenance and support.  Or, the Trustee could be given additional options to benefit your children.