A taxpayer who converted an IRA funded by deductible contributions to a Roth IRA in 2017 has until October 15, 2018, to undo it. This means recharacterizing the new account as a traditional IRA. However, conversions in 2018 and beyond cannot be undone. The Tax Cuts and Jobs Act of 2017 ended this opportunity.
An estate tax and gift tax deduction for assets passing to a spouse. It allows estate and gift transfers completely free of tax.