How to Report 401k Withdrawal on Tax Return (Form 1099-R + 1040)

Reporting a 401(k) withdrawal correctly can help you avoid IRS notices, unexpected taxes, and costly filing mistakes.

Whether you took a cash distribution, an early withdrawal, or completed a rollover, the reporting requirements vary based on the type of distribution and the information on your Form 1099-R.

Here’s exactly how to handle the taxes, form by form, line by line, which tax forms to use, and when additional taxes may apply.

Traditional vs. Roth 401(k)

Before we touch a single form, you need to understand the difference between the two.

Traditional 401(k)

You contributed pre-tax dollars.

The IRS has never touched that money.

So when you withdraw it, they tax every dollar as ordinary income, the same way they’d tax a paycheck.

There’s no capital gains treatment here, and it’s all ordinary income, at whatever marginal rate applies to you that year.

Roth 401(k)

For Roth 401(k), you contribute after-tax dollars.

So, you already paid the IRS on the way in.

If your distribution is qualified —

• Your account has been open for at least five years and
• You’re 59½ or older

..every dollar you withdraw is completely tax-free.

Tax Documents and Withholding Forms

Here’s a quick map of the paperwork landscape before we get into the specifics.

1. Form 1099-R

This is the document your plan administrator sends you after any distribution.

Think of it as your 401(k)’s W-2.

• Box 1 shows the gross amount you received.
• Box 2a shows the taxable portion.
• Box 7 shows a distribution code that tells the IRS what kind of withdrawal it was.

Use the 1099‑R to fill out your tax return. Attach all 1099‑Rs with withheld tax to your 1040.

2. Form 1040, Lines 5a and 5b

• Line 5a is the gross distribution (Box 1 from your 1099-R).
• Line 5b is the taxable amount (Box 2a from your 1099-R).

If you’re doing a rollover, 5b will be zero. If you’re taking a fully taxable traditional withdrawal, 5a and 5b will show the same number.

3. Form 5329

This is the early withdrawal penalty form.

If you have an early distribution subject to the 10% penalty and want to claim an exception (or compute the penalty), file Form 5329 with your return.

In case code 1 is on 1099‑R, and you owe the full 10%, you may instead report the penalty on Schedule 2 and skip 5329.

4. Form W-4P / W-4R

These withholding certificates tell the payer how much federal tax to withhold.

• Use Form W‑4P if your 401(k) distribution is periodic, like an annuity payment.
• Use Form W‑4R if it’s a non-periodic payment or an eligible rollover (e.g., a lump-sum withdrawal).

Otherwise, 20% is automatically withheld on a lump-sum (non-rollover) distribution unless you elect otherwise via W‑4R.

By the way, state withholding rules vary, and some states have optional flat withholding, while others require an election.

Reporting a 401(k) Withdrawal on Taxes

Step 1. Collect Form 1099-R

Before you start your tax return, wait for Form 1099-R from your 401(k) provider.

This form reports your retirement distribution and is required for filing.

Check these boxes carefully:

• Box 1 – Total distribution
• Box 2a – Taxable amount
• Box 4 – Federal tax withheld (if any)
• Box 7 – Distribution code

Common Box 7 codes:

• 7 – Normal distribution (taxable as ordinary income)
• 1 – Early withdrawal (may trigger 10% penalty)
• G – Direct rollover (generally not taxable if properly completed)

Step 2. Confirm Whether the Withdrawal Is Taxable

Now, determine how much of your withdrawal is taxable income.

Traditional 401(k)

• Usually 100% taxable
• Contributions were pre-tax, so withdrawals are treated as income

Roth 401(k)

• May be partially or fully tax-free
• Only taxable if the withdrawal is not qualified

The taxable amount typically flows into:

• Form 1040 – Pensions and Annuities section

Step 3. Enter Form 1099-R Into Your Tax Return

Open your tax software (or paper Form 1040 process) and go to:

Retirement Income / 1099-R Entry Section

You will enter:

• Payer details
• Box 1 amount
• Box 2a amount
• Box 7 code exactly as listed

Important: Do not adjust the numbers unless you are correcting an error or have documented rollover/tax-exempt portions.

Step 4. Report the Income on Form 1040

Once entered, the taxable portion automatically flows into:

• Form 1040, Line 5b (Taxable pensions and annuities)

At this stage, your 401(k) withdrawal is treated like ordinary income and taxed at your marginal rate.

Step 5. Determine if You Owe the 10% Early Withdrawal Penalty

If you are under age 59½, check whether the IRS penalty applies.

If applicable:

• File Form 5329 (Additional Taxes on Qualified Plans)
• Calculate 10% of the taxable portion

Common exceptions include:

• Disability
• Medical expenses above the IRS threshold
• Separation from service after age 55 (401(k) rule)
• Qualified domestic relations order (QDRO)
• Substantially equal periodic payments (SEPP)

If an exception applies, you may reduce or eliminate the penalty, but you must report it properly.

Step 6. Report Federal Tax Withholding

If your 1099-R shows withholding in:

• Box 4 (Federal income tax withheld)

You must include it on:

• Form 1040, Line 25b

This is money already paid to the IRS and will reduce your tax bill or increase your refund.

Step 7. Include State Tax Reporting

Your state return usually mirrors your federal return, but rules vary.

Most states:

• Tax 401(k) withdrawals as ordinary income
• Require full 1099-R reporting

Some states:

• Offer partial or full retirement income exclusions

Enter the same 1099-R details in your state tax section and follow your state’s retirement income rules.

Step 8) Handle Rollovers

If your withdrawal was intended as a rollover:

Direct rollover (Code G)

• Usually not taxable
• Still report on 1099-R
• Must show rollover completed correctly

Indirect rollover

• You received funds first
• Must redeposit within 60 days to avoid taxation

If you missed the 60-day window:

• Entire amount may become taxable
• Penalty may apply if under 59½

Step 9. Review Before Filing

Before submitting your return, confirm:

• 1099-R is fully entered
• Taxable amount matches Form 1040
• Box 7 code is correct
• Form 5329 is included if needed
• Federal withholding is credited
• No missing rollover documentation

Step 10. File Your Return and Store Records

Once filed:

• E-file – no attachments needed
• Paper file – attach Copy B of 1099-R

Federal Tax Return Reporting (Form 1040)

Let’s say you’re 60 years old, you’ve retired, and you withdraw $10,000 from a traditional 401(k).

Here’s exactly what happens:

Your plan administrator sends you a 1099-R.

• Box 1 shows $10,000.
• Box 2a shows $10,000, which is fully taxable — no after-tax basis.
• Box 7 shows code “7,” which means normal distribution (age 59½ or older, no early penalty).

So, On Form 1040:

• Line 5a = $10,000.
• Line 5b = $10,000.

That $10,000 is now added to your other income for the year and taxed at your marginal rate.

Let’s say your total income that year puts you in the 22% federal bracket; you owe $2,200 in federal income tax on that withdrawal.

If the plan withheld 20% ($2,000), you’re close. If they withheld nothing, you owe the full $2,200 at filing.

Early Distributions and 10% Penalty

Withdraw before age 59½, and the IRS hits you with a 10% additional tax on top of ordinary income taxes, unless an exception applies.

• The additional tax is computed on Form 5329, Part I.
• Enter the total premature distribution subject to tax
• Next, list any exceptions on lines 2–10 of Form 5329 (for example, deaths/disability/domestic abuse, etc.).
• The tax (10%) is computed on line 1 (distribution amount × 10%) and reduced by any exceptions (line 10).
• The net extra tax goes on Form 1040 (Schedule 2, line 10, if not filing Form 5329).

Let’s take an example again.

Alice is 45 years old and takes a $10,000 distribution from her traditional 401(k).

Her 1099-R shows $10,000 in Box 1 and $10,000 in Box 2a with code “1” (early distribution, no known exception).

On her return:

• Line 5a = $10,000
• Line 5b = $10,000.

She owes ordinary income tax on $10,000, say $2,200 at 22%.

Plus the 10% early withdrawal penalty: $1,000 on Form 5329 Part I.

Total tax hit: $3,200 on a $10,000 withdrawal.

She walks away with $6,800.

That’s why I always say: if you need the money before 59½, exhaust every other option first.

Exceptions to the 10% Penalty

The IRS does have exceptions. If any of these apply, you still owe income tax, but the 10% extra goes away:

• Death or total disability of the participant
• Separation from service at age 55 or older (for qualified plans)
• Qualified domestic relations order (QDRO) distributions
• Medical expenses exceeding 7.5% of your adjusted gross income
• First-time home purchase (up to $10,000 lifetime)
• Qualified birth or adoption distributions (up to $5,000)
• Reservist called to active military duty
• Substantially equal periodic payments (the 72(t) method — a more advanced strategy)
• Disaster relief distributions designated by the IRS
• Certain higher education expenses

If an exception applies, file Form 5329 and list it there.

If your 1099-R already shows the exception in Box 7, the IRS may not require the form, but file it anyway to document the exception clearly.

Better to have it on paper than to explain yourself during an audit.

Do State Taxes 401(k)

Federal taxes get all the attention, but depending on your state, your 401(k) may or may not be taxed.

Special Situations for 401(k) Tax

Divorce and QDROs

If your 401(k) is divided in a divorce through a QDRO, the tax treatment depends on who receives the money.

Inherited 401(k): What Beneficiaries Owe

If you inherit a 401(k), you report the distributions as ordinary income on your own tax return.

The early withdrawal penalty generally doesn’t apply to inherited distributions; the participant’s death is an exception.

Nonresident Aliens

If you’re a nonresident alien receiving U.S. retirement distributions, the withholding rate is 30%, unless a lower tax treaty rate applies.

Your income is reported on Form 1042-S rather than 1099-R.

Submit Form W-8BEN to the plan administrator to certify your residency status and claim any applicable treaty rate; without it, they’ll withhold at the full 30%.

Excess Contributions

If you contributed more than the annual limit to your 401(k), the excess must be returned.

Corrective distributions are taxed in the year of the original contribution, not the year of the distribution.

So, if you over-contributed, the plan will issue a 1099-R with a specific code (J or S).

Report it as Other Income on Schedule 1.

Using Tax Software vs. Working With a Pro

Most tax software handles 401(k) distributions competently.

TurboTax, H&R Block, and TaxAct all walk you through entering 1099-R information and will automatically populate the right Form 1040 lines, generate Form 5329 if early distribution rules apply, and flag rollover situations.

Where software falls short:

• Complex QDRO situations
• Inherited 401(k) planning involving large accounts and multiple beneficiaries
• State-specific exemptions that require manual entry or local knowledge
• Excess contribution scenarios requiring amended returns
• Large traditional 401(k) balances, where a Roth conversion strategy could meaningfully reduce lifetime taxes

If your situation is straightforward, software handles it fine.

But, for someone navigating a divorce, an inheritance, a large one-time distribution, or any of the special situations listed above, I would recommend paying for a CPA or enrolled agent.

Note: Tax laws change, and individual situations vary. This post is for informational purposes and does not constitute tax or legal advice. Consult a qualified tax professional for guidance specific to your situation.