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I Inherited a Stock Portfolio. What Should I Check First?
An inherited portfolio arrives with someone else’s choices, tax history and risks. Here is what to check first, in order, and why there is rarely a reason to rush.
Key takeaways
- Check the account type first, then cost basis, then concentration. Stock inherited in a taxable account generally takes a basis equal to its value at the date of death (IRS Publication 551), which can sharply cut the tax on selling.
- Inherited IRAs follow separate rules: many non-spouse beneficiaries must empty the account within 10 years, under IRS beneficiary rules.
- Long-held portfolios can be concentrated in a few names. In Exent’s data, 220 of 349 large US stocks fell more than the S&P 500 in the 2007–09 crisis.
- There is rarely a need to act in the first weeks. Gather the facts, then decide, with a tax professional for anything involving sales.
In this article
- I inherited a stock portfolio. What should I check first?
- What should I check in an inherited portfolio?
- What is the step-up in cost basis?
- What if I inherited an IRA or 401(k)?
- How concentrated is the inherited portfolio?
- Common mistakes with an inherited portfolio
- How do I get a second look at an inherited portfolio?
I inherited a stock portfolio. What should I check first?
Start with what kind of account it is and what the holdings are worth on the date of death. Those two facts decide the tax rules and your options. After that, look at the risk: how concentrated the portfolio is and how it overlaps with what you already own.
The portfolio was built for someone else’s age, goals and tax situation. That does not make it wrong for you, but it means every holding deserves a fresh look rather than an automatic keep or sell.
What should I check in an inherited portfolio?
- Account type: taxable brokerage account, inherited IRA or 401(k), or a trust. Each follows different rules.
- Values at the date of death for every holding, usually available from the brokerage or the estate’s representative.
- Cost basis records, so the stepped-up basis is reported correctly when you sell.
- Concentration: the size of the largest holding and the top five as a share of the total.
- Overlap with your own portfolio: the same stocks or the same sectors you already hold.
- Crash loss in dollars: what the holdings would have lost in 2008, 2020 and 2022.
- Costs: expense ratios of any funds and fees on any managed accounts.
- Deadlines: required withdrawals for inherited retirement accounts.
What is the step-up in cost basis?
For inherited property, the basis is generally its fair market value at the date of death, or on an alternate valuation date if the estate’s representative chooses it, according to IRS Publication 551, Basis of Assets. Gains from before the death are then generally not taxed when you sell. An illustrative example:
| Illustrative | Using the original purchase price | Using the stepped-up basis |
|---|---|---|
| Original purchase | $20,000 | |
| Value at the date of death | $120,000 | |
| Sold shortly after for | $121,000 | $121,000 |
| Taxable gain | $101,000 | $1,000 |
Illustrative only. There are exceptions, and property given as a gift during the person’s lifetime follows different basis rules. Confirm your situation with a tax professional. See cost basis for the basics.
What if I inherited an IRA or 401(k)?
Inherited retirement accounts do not get a step-up, and withdrawals are generally taxed as income for traditional accounts. Timing rules apply. Under the IRS page Retirement topics: Beneficiary, a designated beneficiary who is not an “eligible designated beneficiary” generally follows a 10-year rule for owners who died in 2020 or later. Spouses, minor children of the owner, disabled or chronically ill people and beneficiaries not more than 10 years younger than the owner have other options. Because withdrawals add to your taxable income, how you spread them can matter. That is a question for a tax professional.
How concentrated is the inherited portfolio?
Measure the largest holding and the top five as a share of the total. Long-held portfolios can end up dominated by a few stocks that grew for decades. Single stocks can fall much further than the market. In Exent’s data, the S&P 500 fell 56.5% peak to trough in 2007–09, while the median large US stock fell 61.6%, and Citigroup and Bank of America fell 97.9% and 94.0%.
Illustrative: if one stock is 40% of a $400,000 inheritance and it fell like that median stock, the position alone would lose about $99,000. Then check overlap with what you already own. Inheriting bank stocks when you work at a bank, or tech stocks next to your own tech funds, doubles the same bet. The ETF overlap tool and concentration risk explain how to measure it.
Common mistakes with an inherited portfolio
- Selling everything in the first weeks, before the basis, account type and deadlines are clear.
- Keeping everything out of loyalty, even when one stock dominates your total wealth.
- Missing an inherited IRA deadline.
- Looking at the inheritance on its own instead of together with your existing portfolio.
How do I get a second look at an inherited portfolio?
Put the inherited holdings and your own in one view. The statement from the estate’s brokerage lists every position; add your own accounts next to it, then measure concentration, overlap between the two sets and what the combined portfolio would have lost in a past crash. Write down the stepped-up cost basis for each position before anything is sold. For sales, estate questions and inherited IRA withdrawals, work with a qualified tax professional or estate attorney. Our hidden portfolio risks guide covers what else to look for.
How to review an inheritance with Exent
- Upload a screenshot, PDF or spreadsheet of the inherited statement next to your own accounts; no brokerage login.
- Exent shows concentration and correlation clusters across both sets, so you can see where the inheritance doubles a bet you already hold.
- It replays the combined portfolio through 2008, 2018, 2020, 2022 and 2025, and tracks cost basis and P&L per holding.
Frequently asked questions
Generally only on gains after the date of death. Under IRS Publication 551, the basis of inherited property is generally its fair market value at the date of death, or on an alternate valuation date if the estate elects it.
There is rarely a reason to rush. First confirm the account type, the stepped-up values and any deadlines, then review concentration and overlap with your own holdings before deciding.
For owners who died in 2020 or later, many non-spouse beneficiaries must empty the account within 10 years under IRS rules. Spouses and some other eligible beneficiaries have different options.
Use the value at the date of death, which the brokerage or the estate’s representative can usually provide. Keep that record, because you need it when you sell.
Measure what that stock is as a share of your total wealth and what a past crash would cost in dollars. A tax professional can help you weigh the options, since the stepped-up basis may make changes cheaper than they look.
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Educational content, not investment advice. Examples are illustrative; past performance does not guarantee future results.