Step-Up Basis Planning Guide

What’s the single most valuable tax break most affluent families never plan around? The step-up in basis, and almost nobody builds a strategy on it. When you die, the cost basis of your assets resets to their value on the date of death, and every dollar of capital gain you accumulated over a lifetime simply vanishes for your heirs. Your kids could sell the next morning and owe nothing.

How the math actually works

Basis is what you paid. Gain is the difference between basis and what something sells for, and that gain is what gets taxed. Say you bought a stock for $200,000 and it’s worth $1,200,000 when you die. Sell it during life and you’d owe capital gains tax on the $1,000,000. Your heirs inherit it at the stepped-up basis of $1,200,000, sell at $1,200,000, and the gain is zero. A million dollars of taxable appreciation, gone, because you held it one more day.

That’s not a loophole. It’s written into the code, and for families with low-basis stock, real estate, or a long-held business, it’s often worth more than any deduction they’ll ever claim.

The trap that catches careful people

Here’s where the second-order thinking earns its name. The whole estate planning industry trains you to push assets out of your estate. Gift early, gift often, get it off your balance sheet. That advice made sense when the federal exemption was small and a 40% estate tax loomed over ordinary families. It makes much less sense now.

When you gift an appreciated asset during life, your heir takes your basis. The $200,000, not the $1,200,000. You’ve handed them a $1,000,000 unrealized gain along with the gift. So the “smart” early gift can manufacture a capital gains bill that the step-up would have erased for free. I’ve seen families gift low-basis stock to dodge an estate tax they were never going to owe, then watch their kids pay six figures in capital gains they could have avoided entirely. The pitch was confident. The price was hidden.

With the 2026 federal estate exemption permanent at $15,000,000 per person, $30,000,000 for a couple, far more families are now under the line than over it. Under the line, the step-up wins. You want assets in the estate at death, not gifted out of it.

When to gift anyway

The calculus flips when estate tax is actually on the table. Above $30,000,000 a couple faces a 40% federal estate tax that beats the 23.8% top capital gains rate, so freezing or removing appreciation through a grantor trust or other structure can save more than the lost step-up costs. The full comparison lives in step-up basis versus lifetime gifting.

A few other rules worth knowing. Assets in a revocable living trust still get the step-up, so that structure costs you nothing on basis. Assets in most irrevocable trusts may not, depending on how they’re drafted. And a Roth conversion does something a step-up never can: retirement accounts get no step-up at all, so converting tax-deferred money to Roth while you’re alive is one of the few ways to scrub the eventual tax off those dollars for your heirs.

What to do with this

For most readers the move is to stop reflexively gifting your most-appreciated assets and start sorting your holdings by basis. Give away cash or high-basis assets when you want to gift. Hold the low-basis ones and let your heirs inherit them clean. If your estate clears the federal exemption, run the gift-versus-hold math deal by deal, not by slogan.

The step-up is the rare tax break that rewards doing nothing. The skill is knowing when nothing is the play.