How the GOP tax bill will affect your will and what you leave to your spouse

From 2011 through 2017, the estate tax exemption changed slightly year to year due to inflation adjustments. Rather than rewrite wills each year, it often made sense to avoid a specific number and instead include a calculation that instructs the executor to factor in the then-current exemption amount.

“If we don’t review these documents, it could have the devastating consequence of not leaving anything for our spouse,” Dillon said.

The higher estate-tax exemption amount of about $11 million, which will be adjusted annually for inflation, is in effect for tax years 2018 through 2025 before returning to the lower amount (which also will adjusted for inflation). Amounts in excess of the exemption that do not go to a spouse or charity generally are taxed at 40 percent, according to the Tax Policy Center.

This estate-planning strategy — using two trusts to provide for a spouse while using the estate-tax exemption to pass on assets tax-free to children — is common, Dillon said.

“It’s been the most tax-efficient way to do it,” he said. “You take advantage of the exemption, and there’s no estate tax on a transfer to the spouse.”