Current law reduces the taxes that heirs owe on assets that appreciate over time. Say a person buys $1 million worth of stock, and the value of that stock rises to $10 million before the person dies. If the person sold the stock before death, she would owe taxes on a $9 million gain. But if she died first, and her heirs immediately sold the stocks she gave them, they would not owe any capital gains taxes. Under the new proposal, which exempts $1 million in gains, the heirs would owe taxes on the remaining $8 million gain.