Cost Basis of Inherited Stock: Step-Up Rules & Examples

Cost basis of inherited stock is the tax value used to calculate gain or loss when an heir sells shares. Inherited securities are commonly revalued at the date they pass to the heir (often the decedent’s date of death), but rules and practical valuations can vary — confirm the executor’s records and tax guidance before acting FINRA. See IRS Publication 551 for primary guidance.

Educational note: This article is for educational purposes only and does not constitute financial, investment, legal, or tax advice. Finelo does not recommend any security, strategy, platform, or transaction. Investing involves risk, including possible loss of principal. Verify rules, fees, risks, and suitability with official sources or a qualified professional.

What Cost Basis Of Inherited Stock Means

“Cost basis” is the amount used to determine gain or loss when you sell an asset. For ordinary purchases it’s typically what you paid (plus commissions), and for inherited securities the basis is generally fair market value on the decedent’s date of death, a valid alternate valuation date elected for the estate, or another basis required by a specific exception. That documented value is used to compute gain or loss: sale proceeds minus cost basis equals gain or loss.

Key scope points:

• Basis governs tax on a sale; it does not affect everyday account statements until you sell.
• The estate’s executor or administrator typically documents the valuation used when transferring assets to heirs; keep that paperwork.
• Selling inherited securities can generate tax consequences and transaction costs — be prepared for both FINRA.

The executor’s appraisal, market-price records, and any estate-tax return should identify the valuation date and amount used. A transfer date is not automatically the valuation date.

How It Works

Mechanics in three steps:

1. Valuation: Determine fair market value on the decedent’s date of death unless a valid alternate valuation date or another statutory exception applies. That documented valuation becomes the starting point for later gain-or-loss calculations.
2. Holding period and sale: Inherited capital assets are generally treated as held for more than one year, regardless of how long the heir actually holds them. Compute gain or loss using amount realized minus adjusted basis, and reconcile broker reporting to the estate records.
3. Reporting: Your taxable gain (if any) is reported on your tax return according to tax rules that apply to capital gains and losses.

Simple formula example (abstract):

• Cost basis = (documented transfer value) + allocable transaction costs.
• Realized gain = Sale price − Cost basis − Selling costs.

Practical notes:

• Keep the executor’s valuation statement and any estate tax return that records asset values; these are the authoritative sources for the basis the estate used FINRA.
• Expect brokerage-level paperwork after transfer; brokers often allow heirs to attach a basis amount to the inherited account so future 1099s reflect that value.

Worked Example

This is a hypothetical illustration — confirm the estate valuation before relying on it.

Assumptions:

• You inherit 100 shares of Company X.
• Estate records show the shares were valued at $150.00 per share at transfer (documented by the executor).
• There are no unusual estate adjustments; no additional allocable acquisition costs.

Numbers and arithmetic:

• Cost basis (total) = 100 shares × $150.00/share = $15,000.
• Two years later you sell all 100 shares at $170.00/share. Gross proceeds = 100 × $170.00 = $17,000.
• Transaction fee (broker) = $20.
• Realized gain = Gross proceeds − Cost basis − Selling costs = $17,000 − $15,000 − $20 = $1,980.

Interpretation:

• You would recognize a taxable capital gain of $1,980 for that sale (reporting and tax rate depend on your personal tax situation).
• If the estate’s valuation had recorded a different transfer price, the gain calculation would change; preserve the transfer documents.

How to Interpret It

What the basis tells you

• The higher the documented cost basis, the smaller the taxable gain on a sale; conversely, a lower basis increases potential taxable gain.
• Basis affects only tax on sale; it does not change economic ownership or dividend rights while you hold the stock.

When the basis matters most

• If you plan to sell soon after inheriting, accurate transfer valuation determines immediate taxable consequences.
• If you plan to hold long-term, basis still matters because future gains are computed relative to it; tax planning depends on expected holding period and your tax bracket.

Two practical decision frameworks

1. Sell vs. hold (short-term view): If you expect the stock to fall in the near term and the documented basis is high, selling now may crystallize a smaller taxable gain. If basis is low and you expect appreciation, holding may increase future gains.
2. Tax-timing considerations (long-term view): Consider how long you’ll hold and whether realized gains will be taxed at favorable long-term rates; but remember tax rules vary and personal circumstances differ.