Husband and Wife together operated several closely held businesses. The business assets were transferred into a Family Trust. Section 2044 QTIP property is included in a surviving spouse's estate, which files a section 6166 election. Assets included in the QTIP trusts qualified for a section 6166 election at the time of the first spouse's death. Separate assets included in the surviving spouse's estate also qualified as section 6166 closely held businesses.