1040 Lines 4a and 4b: Taxable Amounts, Rollovers, and QCDs

On Form 1040, Lines 4a and 4b are where you report IRA distributions: Line 4a shows the gross amount your custodian paid out during the year, and Line 4b shows just the taxable portion. If the entire distribution is taxable, you leave Line 4a blank and enter the full amount on Line 4b. The numbers come straight from your Form 1099-R, with Box 1 feeding Line 4a and Box 2a (or your own calculation) feeding Line 4b.¹

What Belongs on These Lines

Lines 4a and 4b are reserved for distributions from IRAs only: traditional, Roth, SEP, and SIMPLE. Pensions, annuities, 401(k) distributions, 403(b) plans, governmental 457(b) plans, and military retirement pay all go on Lines 5a and 5b instead.¹ If you received both an IRA distribution and a pension payment in the same year, they go on separate pairs of lines even though both arrived on Forms 1099-R.

Your starting point is Box 1 of Form 1099-R, the gross distribution your IRA custodian paid out.² Box 2a shows the taxable amount as the custodian calculated it, though it often reads “taxable amount not determined,” leaving the math to you.

Getting these lines right matters because the IRS matches your return against the 1099-R your custodian files. Mismatches trigger notices, so the numbers on your return need to reconcile with what the custodian reported, even when the taxable amount you enter is lower than Box 2a.

When the Full Distribution Is Taxable

Most traditional IRA owners made only deductible contributions, so every dollar coming out is taxable. In that case, enter the total on Line 4b and leave Line 4a blank.¹ This trips up a lot of people because it feels backward. The logic: Line 4a exists to show the IRS that a larger amount came out than what you’re reporting as taxable. If nothing about the distribution is tax-free, there’s nothing extra to show.

When You Use Both Lines

You use both 4a and 4b when part of the distribution is not taxable. That happens in a handful of situations:

You have basis in a traditional IRA from nondeductible contributions, so a portion of each distribution recovers already-taxed dollars.
You rolled the distribution over into another retirement account, making some or all of it non-taxable.
You made a qualified charitable distribution directly to a charity, which is excluded from income.
You received a Roth IRA distribution that is partly or fully tax-free.

In each of these, the Box 1 gross goes on Line 4a and the smaller taxable amount goes on Line 4b. If you received multiple IRA distributions during the year, add up all the gross amounts for Line 4a and all the taxable amounts for Line 4b.¹

Line 4c and the Checkbox Codes

The 2025 Form 1040 also includes Line 4c, a set of checkboxes for flagging special situations like rollovers, qualified charitable distributions, or health savings account funding distributions. If you used to write “Rollover” or “QCD” next to Line 4b on older forms, those annotations now go on Line 4c.¹ The check on 4c is what tells the IRS why your Line 4b is smaller than the Box 2a figure on the 1099-R it received.

Nondeductible Contributions and Form 8606

If you ever made nondeductible contributions to a traditional IRA, you have basis in that account, meaning money you already paid tax on. You should not pay tax on it again on the way out. The catch: the IRS does not let you cherry-pick which dollars you withdraw. Every distribution is treated as a proportional mix of taxable and non-taxable money.

This is the pro-rata rule, and it applies across all your traditional, SEP, and SIMPLE IRAs combined. For this calculation, the IRS treats every non-Roth IRA you own as one pool.³ If you have $20,000 in nondeductible contributions spread across three IRAs worth a combined $200,000, only 10% of any distribution is tax-free, regardless of which IRA you draw from.

You report this on Form 8606, which tracks your total basis and determines the non-taxable portion of each year’s distribution. The form uses the year-end total value of all your traditional, SEP, and SIMPLE IRAs plus the distributions you took during the year as the denominator, then divides your total basis into that figure to get the exclusion ratio. The taxable result flows to Line 4b, and the gross distribution goes on Line 4a.

Skipping Form 8606 is a costly mistake. If you had nondeductible contributions and don’t file the form, you risk paying tax twice because the IRS will treat the full distribution as taxable. There is also a $50 penalty for each year you were required to file Form 8606 and didn’t, unless you can demonstrate reasonable cause.³

Roth IRA Distributions on Line 4b

Roth withdrawals follow different rules because contributions go in after tax. A qualified Roth distribution is entirely tax-free and does not appear on Line 4b at all. To qualify, you must have held any Roth IRA for at least five tax years, and one of the following applies:⁴

You are age 59½ or older.
You are disabled under the tax code’s total and permanent disability standard.
You are using up to $10,000 (lifetime limit) for a first-time home purchase.
The distribution goes to a beneficiary or estate after death.

The five-year clock starts on January 1 of the first year you contributed to any Roth IRA, not the specific account you’re withdrawing from. If you opened your first Roth in April 2022 for the 2021 tax year, the five-year period began January 1, 2021, and ends after December 31, 2025.

For non-qualified Roth distributions, the IRS applies ordering rules that work in the taxpayer’s favor. Contributions come out first and are always tax-free. Conversion amounts come next, taxed only if withdrawn within five years of the conversion. Earnings come out last, and only earnings on a non-qualified distribution are taxable and reported on Line 4b.⁵ Because of this ordering, many Roth owners can take sizeable distributions without owing anything, even when the distribution isn’t technically qualified. You still enter the gross on Line 4a; Line 4b holds whatever earnings portion is taxable.

Reporting a Rollover

When you move IRA money into another retirement account, the full amount still shows up on Line 4a, but Line 4b is zero. Check the rollover box on Line 4c to explain the gap to the IRS.⁶

The cleanest approach is a direct rollover, sometimes called a trustee-to-trustee transfer, where the money goes straight from one custodian to another and you never touch it. Your 1099-R will show distribution code G, and Box 2a will already read zero.²

An indirect rollover is riskier. The custodian sends the check to you, and you have 60 days to deposit the money into another eligible account. Miss the deadline and the entire amount becomes taxable on Line 4b, potentially with a 10% early withdrawal penalty on top.⁶ The 1099-R for an indirect rollover often shows the full amount as taxable in Box 2a or marks it “taxable amount not determined.” You override that on your return by entering zero on Line 4b and checking the rollover box on 4c.

Qualified Charitable Distributions

If you are 70½ or older, you can direct up to $111,000 per year (the 2026 inflation-adjusted limit) from a traditional IRA straight to a qualified charity. This is a qualified charitable distribution, and the amount is excluded from your taxable income entirely. It also counts toward your RMD for the year if you have one.

On your return, enter the full distribution on Line 4a. If the entire distribution was a QCD, enter zero on Line 4b and check the QCD box on Line 4c. If only part of the distribution was a QCD, reduce Line 4b accordingly and still check the QCD box on 4c.¹ Your 1099-R will not distinguish the QCD from a regular distribution, so keep your own records, including the acknowledgment letter from the charity.

Where Withholding Goes

Federal income tax withheld from your IRA distribution appears in Box 4 of your 1099-R. That withholding does not go on Lines 4a or 4b. It goes on Line 25b of Form 1040, where it counts as a tax payment against what you owe.¹ Keeping the gross distribution and the withholding on separate lines is what allows the IRS to reconcile the 1099-R with your return: Line 4a matches Box 1, Line 4b reflects the taxable portion after any adjustments, and Line 25b picks up the tax already paid.

1
Internal Revenue Service. Instructions for Form 1040
2
Internal Revenue Service. About Form 1099-R
3
Internal Revenue Service. Instructions for Form 8606
4
Office of the Law Revision Counsel. 26 U.S. Code 408A – Roth IRAs
5
Internal Revenue Service. Roth IRAs
6
Internal Revenue Service. Publication 590-A