What is the federal estate tax exemption per individual for 2025, and what happens to the unused portion of a deceased spouse's exemption under portability rules?

For 2025, the federal estate and gift tax exemption is $13.99 million per individual, up from $13.61 million in 2024. Under the portability election introduced in 2010 and made permanent in 2013, a surviving spouse can claim their deceased spouse's unused exemption (the DSUE) by filing a timely estate tax return (Form 706) even if no estate tax is owed. This allows married couples to effectively shelter nearly $27.98 million from estate taxes in 2025. This elevated exemption is scheduled to sunset at the end of 2025 and drop to roughly half unless Congress acts.