A grandmother buys 1,000 shares of a tech stock for $5,000 in 1995. By 2026 those shares are worth $500,000. She wants to help her granddaughter buy a house. Should she gift the stock today, or hold it and let her granddaughter inherit it?
The right answer can swing the family's after-tax outcome by more than $100,000 — not because of the estate tax, but because of a quiet little provision called Internal Revenue Code Section 1015. Gift the stock, and the granddaughter inherits Grandma's $5,000 cost basis along with the shares. Inherit the stock at death, and that basis "steps up" to fair market value under Section 1014, and roughly $495,000 of built-in gain vanishes for income tax purposes.
For families whose estates fall under the 2026 federal exemption of $15 million per person, this single rule reshapes most lifetime giving decisions. Here's how the basis rules actually work, where the dual-basis trap hides, and how to think clearly about gift-now versus hold-until-death.
The Two Basis Regimes in One Sentence
There are only two ways property changes hands without a sale, and the tax code treats them very differently:
- Section 1015 — Lifetime gifts: The recipient takes the donor's adjusted basis. Built-in gain follows the property.
- Section 1014 — Transfers at death: The recipient takes a new basis equal to fair market value on the date of death. Built-in gain is wiped out for income tax purposes.
That single difference — carryover versus stepped-up — is the engine behind a huge amount of estate planning. The estate tax gets the headlines; basis quietly does most of the work.
How Carryover Basis Works Under Section 1015
When you make a lifetime gift of property, the donee doesn't get a fresh basis. Instead, your adjusted basis tags along.
If you bought stock for $10,000, watched it grow to $80,000, and gave it to your daughter, her basis is $10,000. When she sells for $90,000, she recognizes $80,000 of gain — including the appreciation that happened entirely during your ownership. The gain is taxed at her capital gains rate, generally 0%, 15%, or 20%, plus the 3.8% net investment income tax if applicable.
The holding period also tags along. If you held the asset long-term, the donee's holding period includes yours. A gift of shares you've owned for ten years can be sold by the donee the next day and still qualify for long-term capital gains treatment.
The Gift Tax Adjustment
If you actually paid federal gift tax on the transfer — meaning you used up your lifetime exemption and went into out-of-pocket gift tax — Section 1015(d) lets the donee bump up the basis by a portion of the gift tax attributable to the net appreciation in the gift.
The formula is essentially:
Basis increase = Gift tax paid × (Net appreciation ÷ Amount of gift)
For most families this is a non-issue. The federal lifetime gift and estate tax exemption is $15 million per person in 2026 under the One Big Beautiful Bill Act, so very few donors ever pay actual gift tax. But if you're advising a high-net-worth client whose exemption is exhausted, the gift tax basis adjustment is real money.
The Dual Basis Rule: Where Losses Disappear
The trap inside Section 1015 is the dual-basis rule for property that has dropped in value at the time of the gift.
Imagine you bought a vacation property for $400,000. By the time you gift it to your son, the fair market value has fallen to $250,000. Now there are three possible outcomes when he sells:
- He sells for more than $400,000 (your basis): He uses your $400,000 basis to compute gain.
- He sells for less than $250,000 (the FMV at gift): He uses the $250,000 FMV to compute loss.
- He sells for somewhere between $250,000 and $400,000: No gain, no loss. The "dead zone."
The result is brutal: the built-in loss you accumulated while owning the property simply disappears. Neither you nor your son ever gets to deduct it. This is one reason planners almost universally advise: never gift depreciated property. Sell it yourself, recognize the loss on your own return, and gift the cash.
A Quick Example of the Dead Zone
- Donor basis: $400,000
- FMV at gift: $250,000
- Donee sells at: $325,000
- Gain calculation: $325,000 − $400,000 = no gain
- Loss calculation: $325,000 − $250,000 = no loss
- Reported on the donee's return: zero
This is not a planning hack — it's a baked-in feature of the code. The dual-basis rule is the reason "loss-property" and "gain-property" should be analyzed completely differently in any gifting conversation.
How Stepped-Up Basis Works Under Section 1014
Section 1014 takes a much simpler approach. Property acquired from a decedent gets a new basis equal to its fair market value on the date of death (or six months later, if the estate elects the alternate valuation date).
For our grandmother and her $5,000-basis stock now worth $500,000, the math is:
- If she sells today: $495,000 long-term capital gain, taxed at 23.8% (20% federal cap gains + 3.8% NIIT) = roughly $117,810 of federal income tax.
- If she gifts the stock and her granddaughter sells: same $495,000 gain, same tax.
- If she dies holding the stock and her granddaughter inherits: basis steps up to $500,000. Granddaughter sells the next day at $500,000 and recognizes zero gain.
That's a $117,810 swing on a single position — at the federal level alone, before state income tax.
What Qualifies for Step-Up
Most appreciated assets get a step-up: stocks, bonds, mutual funds in taxable accounts, real estate, closely held business interests, collectibles, cryptocurrency. Critically, the following do not qualify:
- Traditional IRAs and 401(k)s — these are "income in respect of a decedent" (IRD) and pass with the original tax characteristics.
- Annuities — generally retain their original basis.
- Series EE / I bonds with deferred interest — the interest remains taxable to the beneficiary.
That makes the basis calculus very different depending on which assets your client is sitting on. A Roth IRA can be gifted at death without income tax consequences anyway, so the basis question barely matters. A taxable brokerage account full of appreciated stock is exactly where step-up shines.
Community Property's Double Step-Up
In community property states — Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, Wisconsin (and Alaska, Tennessee, Kentucky, Florida, and South Dakota by election) — when one spouse dies, both halves of community property get a step-up, not just the deceased spouse's half. In non-community-property states, only the decedent's half steps up.
This makes community property classification of joint assets one of the single highest-leverage estate planning moves available in those states.
The Real Decision: Gift Now or Wait?
The right answer depends entirely on whether the donor's estate is over or under the federal exemption.
Case 1: Estate Under $15 Million (Most Families)
When there is no federal estate tax bill coming, holding appreciated assets until death is almost always the right call. The estate pays zero federal estate tax on the asset, and the basis step-up eliminates the income tax on the embedded gain. Gifting the same asset triggers carryover basis and a future income tax bill on the donee.
For these families, the planning hierarchy looks like:
- Use the annual exclusion for cash and modest gifts ($19,000 per donee in 2026).
- Hold appreciated assets until death whenever possible.
- Gift cash or high-basis assets if you want to help children/grandchildren now.
- Never gift depreciated property — sell it first, gift the proceeds.
Case 2: Estate Above the Exemption
Here the analysis flips. Every dollar of appreciation in the estate is exposed to a 40% federal estate tax rate. Gifting now removes both the current value and all future appreciation from the estate.
The breakeven question becomes: do I prefer to pay capital gains tax (up to 23.8% federal) on the embedded gain via carryover basis to the donee, or estate tax (40%) on the full fair market value at death?
For high-basis, low-appreciation assets, gifting wins easily. For low-basis, high-appreciation assets, the comparison is closer and depends on:
- The donor's life expectancy (longer life = more compounding outside the estate).
- The expected appreciation rate (higher = gift sooner).
- The donee's tax bracket and ability to defer or shelter gain.
- State estate tax exposure (12 states + DC still have one, often with lower exemptions than federal).
Case 3: The Hybrid Play
Many advisors split the difference: gift the appreciation by transferring the asset into a Grantor Retained Annuity Trust (GRAT), a sale to an Intentionally Defective Grantor Trust (IDGT), or use the spousal lifetime access trust (SLAT) strategies to lock in current exemption while keeping flexibility. These vehicles don't eliminate the basis problem, but they let you control which assets get stepped up at death and which don't.
Common Mistakes Families Make
A few patterns show up repeatedly in real cases:
1. Putting a child's name on the deed. Adding a child as joint tenant on a piece of real estate is a present gift of a half interest. The child takes carryover basis on that half, forfeiting half of the step-up that would have occurred at death.
2. Gifting the family home to children to "avoid probate." Same problem at a larger scale. The home you bought for $80,000 that's worth $1.2 million today loses an $1.12 million basis step-up if you gift it before death. A revocable living trust achieves the probate goal without sacrificing basis.
3. Gifting low-basis stock during retirement to pay tuition. The donee gets carryover basis and a future tax bill. If the parent's estate will fall under the exemption, selling and gifting cash (or paying tuition directly to the institution under the §2503(e) exclusion) is usually cleaner.
4. Forgetting that retirement accounts don't step up. Children inheriting a $1 million traditional IRA owe ordinary income tax on every distribution. Roth conversions during life — using the parent's lower tax bracket — can be more valuable than any basis move.
5. Ignoring state law on community property. Married couples in non-community-property states who relocate to a community-property state can sometimes recharacterize joint assets to capture the double step-up. This is highly technical and requires real legal advice, but the savings can be enormous.
A Quick Decision Framework
When a client (or your own parent) asks "should I give this to my kids now?", run through these questions in order:
-
Is the asset worth more or less than its basis?
- Worth less → never gift; sell first and gift cash.
- Worth more → continue.
-
Will the donor's estate exceed the federal exemption ($15M per person in 2026)?
- No → strongly prefer holding for step-up.
- Yes → analyze gift-now vs. hold-and-pay-estate-tax.
-
What's the donee's tax bracket?
- Higher than donor's expected estate tax rate → less favorable for gifting.
- Lower → gifting low-basis assets can shift gain into a cheaper bracket (subject to kiddie tax rules for minors).
-
What's the holding horizon?
- Short — donee plans to sell soon → carryover basis pain is immediate; consider alternatives.
- Long — donee will hold for decades → embedded gain compounds with the asset.
-
Is there a state-level wrinkle?
- Community property recharacterization, state estate tax, state income tax on the donee — all can flip the answer.
Keep Your Basis Records Clean from the Start
The whole carryover-vs-step-up analysis only works if the cost basis is actually known. In practice, families lose enormous amounts of money simply because no one tracked basis: the original cost of a 1985 home renovation, the reinvested dividends in a brokerage account moved twice between custodians, the basis of inherited mutual fund shares passed down through two generations.
Good recordkeeping is not glamorous, but it is the prerequisite for every basis-saving strategy in this article. Keep purchase confirmations. Track improvements to real estate. Document gifts in writing with date, fair market value, and donor's basis. Hold onto Form 709s. When inheriting property, get a written appraisal contemporaneous with the date of death.
Treat your basis records the way you treat your insurance policies: boring until you need them, and then more valuable than almost any other document in the file.
Keep Your Financial Records Organized from Day One
Whether you're tracking the cost basis of a long-held stock position, documenting improvements to a property you may someday gift, or recording the date-of-death value of inherited assets, the underlying need is the same: a clean, durable, and auditable record. Beancount.io gives you plain-text accounting that's transparent, version-controlled, and AI-ready — exactly the kind of system that makes basis questions answerable years or decades later. Get started for free and put your financial life on a foundation you can actually trust.