The idea of “portability” is an important part of many estate plans. Portability is technically an informal word referring to a federal tax-saving option using the deceased spouse’s unused exemption (DSUE). Essentially, portability is a tool for married couples that, when used prudently, can shave millions of dollars off an estate tax bill.
Under the current law, assets under $5.34 million are exempt from the federal estate tax (though the New York tax kicks in far lower at $1 million). Importantly, there are unlimited tax-free transfers allowed between spouses. That means that if one spouse dies and leaves everything to the other, then there will not be a federal estate tax burden, regardless of how many assets are passed on.
However, when the surviving spouse passes away and transfers those assets to others–perhaps adult children–then the tax would apply to assets over the individual exemption level of $5.34 million. But portability changes that. Instead of using only an individual exemption, a surviving couple may be able to use any unused exemption from their former spouse in addition to their own. This means that up to $10.68 million may be exempt from the tax. In short, portability can save an estate millions of dollars in taxes.