1099-R Box 9b: Taxable Income, Simplified Method, and Basis

Box 9b on Form 1099-R reports the total after-tax money you put into a retirement plan over your working years. That figure, sometimes labeled “total employee contributions” or “total investment in the contract,” is your cost basis in the plan. You use it to calculate how much of each pension or annuity payment you can leave out of taxable income, because those dollars were already taxed on the way in and should not be taxed again on the way out.¹

What Box 9b Reports

If you contributed $40,000 of after-tax dollars to a pension over your career, Box 9b should show $40,000. That amount gets recovered tax-free, spread across your retirement payments, so only the earnings and employer contributions are taxed.

The box applies mainly to periodic payments from qualified employer plans: defined-benefit pensions, 403(b) plans, and certain annuities where some or all of what you put in was after-tax.¹ For traditional IRAs, Box 9b is almost always blank because those contributions were typically pre-tax. If you made nondeductible IRA contributions, your basis is tracked separately on Form 8606, not through Box 9b.²

Why the Box May Be Blank

Plan administrators are not required to fill in Box 9b. The IRS instructions say payers “may choose to report” total employee contributions there, and that’s it.³ So a blank Box 9b falls into two very different situations, and the distinction matters.

The first is simple. All your contributions were pre-tax, there’s no basis to report, and the gross distribution in Box 1 is generally the same as the taxable amount in Box 2a. Nothing more to do.

The second is where people lose money. Because reporting is optional, a blank box can just mean the administrator didn’t fill it in. If you made after-tax contributions, you still have basis even if the form doesn’t show it. Treating the full distribution as taxable in that case means overpaying tax every month for the rest of your retirement.

Box 9b Compared With Box 5

Box 5 and Box 9b both deal with employee contributions but answer different questions. Box 5 shows the portion of basis recovered tax-free in the current year for periodic payments, or the total basis available for tax-free recovery in a lump-sum distribution. Box 9b, when filled in, shows the cumulative after-tax contributions you have not yet recovered. For a total lump-sum distribution, the payer reports the full basis in Box 5 rather than Box 9b.³ For monthly pension payments, Box 9b is the number that feeds the Simplified Method.

Using Box 9b to Calculate Taxable Income

When Box 9b shows a value, Box 2a is blank, and Box 2b is checked “Taxable amount not determined,” you calculate the taxable portion yourself.¹ Most qualified plan recipients use the Simplified Method.

The Simplified Method

The Simplified Method divides your total basis (Box 9b) by a set number of anticipated monthly payments based on your age when payments began. The result is a fixed dollar amount excluded from income each month.⁴ For a single-life annuity, the payment factors set by statute are:⁵

Age 55 or under: 360 payments
Age 56 to 60: 310 payments
Age 61 to 65: 260 payments
Age 66 to 70: 210 payments
Age 71 or older: 160 payments

Joint-and-survivor annuities use a separate table based on the combined ages of both annuitants, ranging from 410 payments at combined age 110 or under down to 210 payments at combined age 141 or older.

An example. You retire at age 62 with $52,000 of after-tax contributions shown in Box 9b. The table assigns 260 payments for ages 61 to 65. Dividing $52,000 by 260 gives a monthly tax-free exclusion of $200. If your monthly pension is $2,000, you report $1,800 as taxable income and exclude $200 as a return of your own after-tax money.

The total you can exclude is capped at your full basis. Once you have recovered $52,000, every dollar of every future payment is fully taxable. You track the running total on the Simplified Method Worksheet in the Form 1040 instructions or in IRS Publication 575.⁴

When the General Rule Applies Instead

The General Rule is a different, more complex calculation for nonqualified annuities (such as commercially purchased annuities) and for certain qualified plans where the Simplified Method does not apply — primarily when the annuitant is 75 or older on the annuity starting date and payments are guaranteed for at least five years.⁶ It uses actuarial life expectancy tables to figure an exclusion percentage. Most qualified plan recipients will not need it; Publication 939 walks through the math if you do.

If Box 9b Looks Wrong or Missing

The burden of proving after-tax contributions falls on you. If you cannot document them, the IRS treats your basis as zero and taxes the full distribution. People who spent 30 years at one employer often assumed someone else was keeping track, and often nobody was.

If you think Box 9b is wrong or should have a value, start with the plan administrator. They can review records and issue a corrected 1099-R. To support your position, pull together whatever you have:

Past Forms 1040 from years you made after-tax contributions
Annual benefit statements showing cumulative employee contributions
Prior Forms 1099-R that may have included Box 9b values
Copies of Form 8606 for any IRA basis⁷

General IRS recordkeeping guidance points to the period of limitations, usually three years from filing.⁸ For retirement basis, keep the records longer than that. Basis recovery can span decades, and you may need to prove a 1995 contribution when you take distributions in 2035.

For traditional IRAs with nondeductible contributions, the basis never shows up on the 1099-R at all. You report and track it on Form 8606 each year. Missing a required Form 8606 filing carries a $50 penalty per occurrence, and, more consequentially, it can erase the paper trail you need to claim tax-free recovery later.⁷

Unrecovered Basis at Death

If you die before recovering your entire after-tax investment, the remaining amount does not vanish. The unrecovered basis is deductible on the annuitant’s final tax return.⁵ Using the earlier example, if you had $52,000 of basis and recovered $40,000 tax-free before dying, the remaining $12,000 can be claimed as an itemized deduction on the final return.⁹ The statute treats this deduction as attributable to a trade or business, which lets it contribute to a net operating loss if the final return has limited income.

For joint-and-survivor annuities, the surviving spouse keeps using the same monthly exclusion the primary annuitant was using. Exclusions continue until the total number of payments reaches the figure from the original Simplified Method calculation, or until the full basis has been recovered, whichever comes first. If the surviving spouse also dies before full recovery, the same deduction applies on their final return.¹⁰

Other Things That Can Change the Number

Retired Public Safety Officers

Eligible retired public safety officers, including law enforcement, firefighters, and emergency medical personnel, can exclude up to $3,000 per year from retirement plan distributions if the money goes directly to pay health or long-term care insurance premiums. This exclusion is separate from basis recovery through Box 9b and reduces the otherwise taxable amount of the pension payment.¹¹ The $3,000 cap is not indexed for inflation. The premiums must be paid directly from the plan; reimbursing yourself from a personal account does not qualify.

Rollovers That Included After-Tax Money

If you rolled after-tax contributions from a qualified plan into an IRA, tracking that basis is now on you. The rollover itself should have been reported on a Form 1099-R with the basis amount shown in Box 5, and any after-tax dollars that landed in a traditional IRA carry forward as nondeductible contributions tracked on Form 8606.³ People who made these rollovers years ago sometimes stopped filing 8606s for the receiving IRA, which effectively erases the basis trail. If you have done such a rollover, confirm the 8606 chain is intact.

Getting the Basis Wrong

Underreporting taxable income by overstating basis, or by claiming basis you cannot prove, can trigger the IRS accuracy-related penalty of 20% on the underpaid tax when there is a substantial understatement.¹² Going the other direction, failing to claim legitimate basis is not penalized, but you are handing the IRS money you do not owe. Correcting an overpayment later means filing amended returns, which is possible but much more work than getting the number right the first time.

1
Internal Revenue Service. Form 1099-R 2025 Distributions From Pensions, Annuities, Retirement or Profit-Sharing Plans, IRAs, Insurance Contracts, etc.
2
Internal Revenue Service. About Form 8606, Nondeductible IRAs
3
Internal Revenue Service. Instructions for Forms 1099-R and 5498 (2025)
4
Internal Revenue Service. Topic No. 411, Pensions – The General Rule and the Simplified Method
5
Office of the Law Revision Counsel. 26 U.S. Code 72 – Annuities; Certain Proceeds of Endowment and Life Insurance Contracts
6
Internal Revenue Service. Publication 939 (12/2025), General Rule for Pensions and Annuities
7
Internal Revenue Service. Instructions for Form 8606
8
Internal Revenue Service. Topic No. 305, Recordkeeping
9
Internal Revenue Service. Publication 575, Pension and Annuity Income
10
Internal Revenue Service. Tax Guide to U.S. Civil Service Retirement Benefits
11
Office of the Law Revision Counsel. 26 U.S. Code 402 – Taxability of Beneficiary of Employees Trust
12
Office of the Law Revision Counsel. 26 U.S. Code 6662 – Imposition of Accuracy-Related Penalty on Underpayments