IRS Forms for Inherited IRAs and Retirement Accounts: What to File and When

The IRS does not send you a neatly organized packet when someone dies and leaves you a retirement account. You are expected to know which forms to file, which publications explain the rules, and when each deadline hits. Miss one, and you face penalties that range from a 25% excise tax on a missed RMD to interest charges on late-filed returns.

Here is every form and publication that matters, in the order you are likely to need them.

Form SS-4: Estate Employer Identification Number

If the inherited retirement account passes through the deceased's estate — because the estate was named as the beneficiary, no beneficiary was designated, or the named beneficiary predeceased the owner — you need an EIN before the custodian will release funds. The EIN functions as the estate's tax ID, separate from the deceased's Social Security number.

Apply online at irs.gov (the EIN assistant takes about five minutes and issues the number immediately) or file Form SS-4 by fax or mail. You cannot use the deceased's SSN on the estate's tax returns.

Form 1099-R: Distributions From Retirement Accounts

You do not file this form — the custodian issues it. But you need to understand it because the numbers on the 1099-R drive your tax return.

After any reportable distribution from an inherited IRA, 401k, 403b, or other retirement plan, the custodian sends Form 1099-R to the recipient and files a copy with the IRS. The recipient's copy is generally due by January 31 of the following year; the IRS copy is due February 28 on paper or March 31 electronically, subject to weekend and holiday adjustments. Box 7 contains a distribution code that tells the IRS the nature of the withdrawal: code 4 (death) is the most common for inherited accounts. A distribution paid to you as beneficiary after death is reported to you and generally goes on your return; if the estate receives it, the estate reports it. Distributions the deceased received before death belong on the deceased's final return.

Watch for errors. If the custodian codes the distribution incorrectly (code 1 instead of code 4, for example), it can trigger an early withdrawal penalty flag. Contact the custodian to issue a corrected 1099-R before you file.

Form 1040: Deceased's Final Individual Tax Return

The deceased's final Form 1040 covers January 1 through the date of death. It reports any distributions the deceased received before dying, including any partial RMD they took during the year. The executor or surviving spouse files this return.

If the deceased had reached their required beginning date and died before taking the full year-of-death RMD, the beneficiary must withdraw the remaining amount by December 31. A distribution paid to a beneficiary is reported by that recipient, not on the deceased's final Form 1040.

Deadline: April 15 of the year following death, or October 15 with an extension (Form 4868).

Form 1041: Estate Income Tax Return

If the estate receives income — including distributions from retirement accounts — the executor files Form 1041. This applies when the estate is the IRA beneficiary, or when distributions pass through the estate before reaching individual beneficiaries.

Estate tax brackets are compressed: the 37% rate kicks in at roughly $15,000 of retained income. Distributing income to beneficiaries within the tax year (and reporting it on Schedule K-1) pushes the tax liability onto the beneficiaries' individual returns, where the brackets are far wider. Your CPA should be coordinating this.

Deadline: April 15 of the year following the estate's tax year-end (which is either the calendar year or a fiscal year elected by the executor).

Publication 590-B: Distributions From IRAs

This is the reference document for inherited IRA rules — not a form you file, but the publication you (or your CPA) read to determine your distribution requirements. It covers:

• The three beneficiary categories (eligible designated beneficiary, designated beneficiary, non-designated beneficiary)
• The 10-year depletion rule and when annual RMDs are required within that window
• Life expectancy tables for stretch distributions (Table I — Single Life Expectancy)
• The year-of-death RMD calculation
• Roth IRA inherited distribution rules

The IRS updates Publication 590-B annually. Use the version for the current tax year — the rules changed significantly with the SECURE Act 2.0 final regulations (July 2024), and older editions will mislead you on the annual RMD requirement during the 10-year window.

Form 5329: Excise Tax on Missed RMDs

If you miss a required minimum distribution — whether the deceased's final year-of-death RMD or your own annual RMD as a beneficiary — Form 5329 is where you report it and pay the penalty. The excise tax is 25% of the shortfall amount.

Under SECURE 2.0, if you correct the missed RMD within two years (take the distribution and file Form 5329 with a request for the reduced rate), the penalty drops to 10%. Attach a brief explanation of the error and the corrective action you took.

The IRS waived these penalties for certain annual RMDs within the 10-year window for tax years 2021 through 2024. That relief expired on December 31, 2024 — starting with the 2025 tax year, annual RMDs are mandatory when the original owner died after their required beginning date.

Form 8606: Nondeductible IRA Contributions

If the deceased made nondeductible (after-tax) contributions to a traditional IRA, a portion of every distribution from the inherited account is tax-free. Form 8606 tracks the basis — the total of all nondeductible contributions — and calculates the taxable and nontaxable portions of each distribution.

Check the deceased's prior tax returns for filed Form 8606s. If they made after-tax contributions but never filed this form, the basis still exists — you just need to reconstruct it from contribution records. Without Form 8606 and adequate records of the basis, you risk being unable to claim the nontaxable portion of the distribution.

Custodian-Specific Claim Forms

These are not IRS forms, but you will need them alongside the IRS paperwork:

• Vanguard Form S737 — Transfer Due to Death of Account Owner
• Fidelity death claim packet — mailed or emailed after you call their estate services line
• Primerica POL-RPDE — Retirement Plans Death Distribution Form (administered by BNY; requires death certificates stating cause and manner of death)

Each custodian's forms are different. Call the estate services line first to confirm exactly which forms and documents they require — do not assume one custodian's process matches another's.

The Retirement Account Claims toolkit includes a complete IRS form checklist organized by your specific situation (spouse vs. non-spouse, estate beneficiary vs. named beneficiary, traditional vs. Roth), so you file the right forms by the right deadlines without second-guessing.