Guide
What records should I find if an inherited traditional IRA may have nondeductible contributions?
Published
Look for the deceased owner's Forms 8606 and supporting records, contribution statements and distribution records. Keep the inherited IRA's evidence separate from your own IRA records and from IRAs inherited from other people. Ask a tax professional to review any missing years or conflicting information before you treat the account balance as the answer. An inherited traditional IRA's contribution basis is not the date-of-death value used in some inherited-property questions.
This US guide is a records-preparation aid, not a tax calculation or instructions for completing a return. It does not determine whether the account has basis, how much of a withdrawal is taxable or which distribution you should take. The IRS sources below are the currently available 2025 editions; use the instructions for the tax year being reviewed with your preparer.
Key takeaways
- Preserve evidence of nondeductible contributions and earlier distributions, not only a recent account balance.
- Label each record by the person and IRA history it concerns, its tax year and its source.
- Keep inherited and personal IRA records distinct. Do not combine figures to make an incomplete packet look complete.
- Record missing or inconsistent evidence as an open question, not an assumed zero.
- Give the preparer a clear record inventory and the actual documents through an agreed secure process.
What does IRA contribution basis mean here?
The IRS's Publication 590-B says that if a person who died had basis in a traditional IRA because of nondeductible contributions, that basis remains with the IRA. It also explains limits on combining that basis with your own traditional IRAs or IRAs inherited from other people. A surviving spouse who chooses to treat the IRA as their own is an exception to that discussion. [1] Do not apply the nonspouse rule to a spouse's choices without review.
This is a different question from the market value of inherited stocks or property at death. An account statement's balance does not, by itself, establish the IRA's nondeductible-contribution history. The broader inheritance guide explains how to identify different inherited assets and which questions go to an executor, custodian or professional. Start there if you are not sure whether the asset is an IRA at all.
Within this guide, the job is to find and identify evidence. It is not to add up every historical contribution or decide that a missing form means no basis existed. The tax treatment belongs in a qualified review of the relevant records and applicable rules.
Which forms and records should I look for?
The IRS's Form 8606 instructions list records to keep to verify the nontaxable part of IRA distributions. They include Forms 8606 with supporting statements, attachments and worksheets for applicable years; Forms 5498 or similar contribution statements; certain year-value statements; and Forms 1099-R or W-2P for distribution years. [2] This list points to evidence to seek, not a conclusion that every item applies to every beneficiary.
For the deceased owner's IRA history, ask the executor or other authorized contact which relevant tax records can be made available. Ask the institution what contribution, distribution and account-history records it can provide through its process. A tax preparer can explain which years and documents are needed for the particular review. Do not assume that an institution possesses the person's complete tax-return history.
Keep the actual source document, not only a figure copied into a note. If you receive a partial return without its Form 8606 or attachments, identify that limit. If a statement does not distinguish a deductible from a nondeductible contribution, do not supply that classification yourself.
How can I organize the packet without calculating basis?
Make a private inventory with a few fields that let the preparer locate the evidence. Keep client identifiers out of any public example or ordinary inquiry form. Use the preparer's agreed secure exchange process for the actual documents.
Record and tax year
Name the document and the year it concerns. Keep the tax year separate from the date you downloaded or received the copy. A document obtained today may describe a much earlier transaction or return.
Person and account history
Identify internally whether the document concerns the person who died, your own IRA or another inherited IRA. If you cannot tell, label that question. Do not file all IRA forms in one undifferentiated stack and leave the preparer to discover which history each belongs to.
Source and completeness
Record who supplied the copy and whether attachments, worksheets or relevant pages are missing. A summary of a conversation is different from a filed form. A form supplied by an institution is different from a tax-return attachment. Preserve those distinctions.
Question for review
Describe what you need explained: a missing year, an unclear contribution classification, a prior distribution record or a discrepancy between two documents. Do not turn the question into a proposed tax answer.
This inventory is an original organizing aid, not an IRS-prescribed form. It helps you hand over the packet and its limits; it does not establish that the evidence is sufficient.
Why keep different IRA histories separate?
Publication 590-B says that, unless the surviving-spouse own-treatment exception applies, inherited traditional IRA basis cannot be combined with basis in your own traditional IRAs or traditional IRAs inherited from other decedents. The Form 8606 instructions also explain separate forms when they are required for IRAs inherited from more than one decedent. [1][2]
Keep the records separated so the preparer can apply those rules. This does not mean you should decide how many forms to file from the number of folders. The filing question depends on the distributions, basis and circumstances the preparer reviews.
For a fictional example, one folder contains records from Person A's IRA and another contains the beneficiary's personal IRA records. A missing attachment in Person A's folder is not filled by a statement from the personal IRA. The inventory records the missing attachment and who is being asked for it. No values or taxable percentages are calculated.
What if records are missing or disagree?
Keep both versions and write down the precise difference. A recent note saying "all contributions were deductible" and an older Form 8606 that raises a question should not be resolved by choosing the easier document. Give the preparer the documents and their provenance.
Ask what evidence can be obtained and who can request it. Some records may be held by an authorized estate contact, an earlier preparer or the financial institution. Access is not assumed: ask the relevant party about their process and the authority they need. Do not request another person's tax records by pretending to be them.
Track a request separately from its result. "Asked for earlier Forms 8606" is not "forms received." "Forms received" is not "basis determined." A response may fill one gap while leaving another open. Keep that remaining question visible rather than marking the whole IRA reviewed.
What should I ask the tax professional?
Ask which records are needed to review the inherited IRA's contribution basis and prior distributions. Explain what you have, what is missing and which other IRA histories must remain separate. Ask which tax year's forms and instructions apply to the intended filing.
The Form 8606 instructions say an inherited traditional IRA distribution with basis can require Form 8606 and that more than one form may be needed. [2] That is a reason to ask a precise filing question, not a universal instruction that every inherited IRA beneficiary must file the form.
This packet does not resolve an inherited IRA's distribution schedule, a transfer or a spouse's election. Keep those questions separately identified. A better source packet can make the conversation clearer without settling every decision connected to the account.
The bottom line
Find the relevant Forms 8606 and supporting contribution and distribution records, preserve their sources and keep different IRA histories apart. Leave missing evidence unresolved for a tax professional. Do not substitute an account balance or inherited-property valuation for the IRA's contribution-basis history. The result here is a usable records handoff, not a completed tax calculation.
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Common questions
Is inherited IRA contribution basis the account's value on the date of death?
No. This guide concerns evidence of nondeductible traditional IRA contributions and their treatment within the IRA history. Inherited-property valuation is a different question.
Does a missing Form 8606 prove there was no basis?
No conclusion is established by this records exercise. Identify the missing evidence and ask the preparer what further records or review are needed.
Can I combine inherited IRA records with my own IRA records?
Keep the histories distinguishable for review. Publication 590-B explains limits on combining basis and a surviving-spouse exception; do not apply the exception without checking the circumstances.
Must every inherited IRA beneficiary file Form 8606?
No universal filing instruction is given here. Ask the preparer to apply the relevant year's instructions to the distributions and evidence in your case.
Can this inventory tell me how much of a withdrawal is taxable?
No. It organizes source records and open questions. It does not calculate a taxable amount or complete a return.
Sources
[1] IRS, Publication 590-B (2025), What if You Inherit an IRA?