When the federal estate tax exemption is high, the issue of how to apportion death taxes is of less concern to many families. But this issue can cause controversy with taxable estates, blended families, and certain types of assets. If the decedent’s will or trust is silent on the issue of tax apportionment or the decedent died intestate, state law provides default rules that determine which interests or assets in a decedent’s estate bear the burden of paying death taxes. If a certain interest is insufficient to pay the net tax attributable to property passing under the terms of the trust, state law often also provides an order of priority for payment of the balance of the tax owed. However, the terms of the decedent’s will or trust can override these rules; that is, everyone has the opportunity to direct how taxes (and expenses, for that matter) will be paid. In a taxable estate, this may be the most important provision in the testamentary instrument.