The American Taxpayer Relief Act of 2012 made permanent changes to the federal estate tax law, including establishing a $5 million exemption, indexed for inflation.

The new exemption amount means approximately 4,000 estates could still cross the threshold and be subject to estate tax, according to the Tax Policy Center. This number is fewer than the 7,000 estates subject to tax under 2009’s $3.5 million exemption amount, and well below the number of estates that would have been taxable under a full sunset of the 2001 law.

Given the new clarity around estate taxes, tax and financial advisors should review the new guidelines with clients to determine how these changes may affect existing estate plans.