How to Read a CSA 1099-R: Boxes, Simplified Method, and Codes

The CSA 1099-R is the tax form the Office of Personnel Management sends every federal retiree each January, and reading it comes down to five boxes: Box 1 (what OPM paid you), Box 2a (what’s taxable), Box 4 (federal tax already withheld), Box 5 (your own contributions recovered tax-free plus certain insurance premiums), and Box 7 (a code describing the type of payment). The “CSA” prefix on your claim number means you are the retiree; a “CSF” prefix means you are receiving a survivor annuity.¹ OPM posts the form to Retirement Services Online in the third week of January and mails paper copies by January 31.²

Box 1: Gross Distribution

Box 1 is the total OPM paid you during the calendar year. It includes both the taxable and non-taxable portions of your annuity, and it also captures money OPM withheld on your behalf for health insurance premiums or court-ordered deductions. The IRS treats those as amounts paid to you even though the cash never reached your bank account.

Box 2a: Taxable Amount

Box 2a is the figure that flows to your Form 1040. It equals Box 1 minus the tax-free recovery of your own after-tax contributions (your cost basis). For most retirees OPM does this math for you using the rules in IRS Publication 721.³

Sometimes Box 2a reads “Unknown,” or the “Taxable amount not determined” box is checked. That means OPM could not calculate the tax-free portion for you. It happens most often in your first year of retirement, when cost-basis records are incomplete, when you elected an alternative form of annuity, or when you retired on disability.² When that happens, you run the calculation yourself with the Simplified Method described below.

Box 4: Federal Income Tax Withheld

Box 4 shows the federal income tax OPM already withheld from your monthly payments. It works exactly like paycheck withholding: it counts as a payment against your total tax liability when you file. If you never selected a rate, OPM defaults to the IRS standard of single with no adjustments, which usually pulls more than a married filer actually owes.²

Box 5: Employee Contributions and Insurance Premiums

Box 5 is two numbers combined: the amount of your own retirement contributions recovered tax-free during the year, and any after-tax health or accident insurance premiums OPM deducted from your annuity. The recovered contributions are the same tax-free slice used to build Box 2a. OPM breaks down what went into Box 5 in the explanatory notes that accompany the form.²

Box 7: Distribution Code

Box 7 carries a single code that tells the IRS what kind of payment you received. It matters because it decides whether special rules apply.⁴ The codes most federal annuitants see:

Code 7, normal distribution. Standard for a retiree age 59½ or older receiving regular annuity payments.
Code 4, death benefit. Payments to a surviving spouse or other beneficiary.
Code 3, disability. A federal employee who retired on disability before minimum retirement age. These payments are taxed as wages, not pension income, until you reach minimum retirement age.
Code 1 or 2, early distribution. Someone separated from service and received a lump-sum refund of contributions before age 59½. May trigger the 10% early withdrawal penalty.
Code G, direct rollover to an IRA or another qualified plan. No immediate tax owed.

Calculating Box 2a Yourself With the Simplified Method

Every dollar you contributed to CSRS or FERS while working was already taxed. That total is your cost basis, and the IRS lets you recover it tax-free by spreading it across a set number of monthly payments. This is the Simplified Method, and it is mandatory for any annuity with a starting date after November 18, 1996.⁵

Divide your total cost basis by the divisor from the IRS table that fits your situation. That gives you a fixed monthly tax-free amount. Multiply by the number of months you received payments during the year, subtract from Box 1, and the remainder is your Box 2a.³

Single-Life Annuities

If your annuity carries no survivor benefit, or it started before 1998, use the divisor for your age at the annuity starting date:

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

Joint and Survivor Annuities Starting After 1997

If your annuity started after 1997 and provides a survivor benefit for your spouse, use the divisor for the combined ages at the annuity starting date:³

Combined ages 110 or under: 410
111 to 120: 360
121 to 130: 310
131 to 140: 260
141 or older: 210

A worked example. You retired at 62 with a $52,000 cost basis and no survivor benefit. Your divisor is 260. Your monthly tax-free amount is $52,000 ÷ 260 = $200. Over a full year that shelters $2,400. If Box 1 reads $36,000, your Box 2a is $33,600. Publication 721 includes Worksheet A for stepping through this line by line.³

When the Tax-Free Portion Runs Out

The monthly exclusion is not permanent. Once you have recovered your entire cost basis, the whole annuity becomes fully taxable. In the example above, that happens after 260 months of payments. From then on, Box 1 and Box 2a will show the same number.

If you die before recovering the full cost basis, the unrecovered amount is not lost. It can be taken as a deduction on your final income tax return, and the IRS allows it to be treated as a net operating loss that can offset other income on that final return.⁶ Whoever prepares the final return should check the annuity records for it.

If Your Form Shows Code 3 (Disability)

Federal employees who retired on disability before minimum retirement age face different rules. During that period the payments are taxed as wages rather than pension income.⁷ Report them on the wages line of Form 1040 (line 1h), not on the pension and annuity lines.⁸ Box 2a on a Code 3 form is often marked “Unknown,” so the taxable amount is yours to calculate. Once you reach minimum retirement age, payments switch to pension treatment and you begin using the Simplified Method like any other retiree.

If Your Form Is a CSF (Survivor Annuity)

When a federal retiree dies and a surviving spouse or other beneficiary begins receiving a survivor annuity, OPM issues a separate 1099-R with a CSF claim number and Code 4 in Box 7. For tax purposes the survivor keeps recovering the deceased retiree’s unrecovered cost basis, using the same exclusion that applied to the original annuity, until the entire cost basis has been recovered.⁹ For annuities starting after 1986, the total exclusion is capped at the original net cost.³

The Public Safety Officer Exclusion Is Not on the Form

If you retired as a law enforcement officer, firefighter, chaplain, or a member of a rescue squad or ambulance crew, you can exclude up to $3,000 per year of your annuity to pay for health or long-term care insurance premiums for yourself, your spouse, or your dependents.⁵ This exclusion does not appear in Box 2a. You claim it by writing “PSO” next to line 5b on Form 1040 and reducing the taxable amount by the smaller of $3,000 or the premiums you actually paid. You cannot also deduct those premiums as a medical expense.

Getting a Duplicate or Fixing an Error

If you lose the form or never receive it, sign in to OPM Retirement Services Online, where you can view and print current and prior-year 1099-Rs immediately.¹⁰ Without internet access, call OPM’s Retirement Information Center at 1-888-767-6738 and request a paper copy.

If a figure on the form looks wrong, send OPM a written request identifying the specific error with supporting documentation. If OPM agrees, it issues a corrected 1099-R; use that version when filing. If OPM does not respond in time, call the IRS at 800-829-1040. The IRS will contact OPM and send you Form 4852, a substitute you complete with your best estimate of the correct figures and attach to your return.¹¹ If a corrected form arrives later and its numbers differ from your estimate, file an amended return on Form 1040-X.

1
U.S. Office of Personnel Management. Get Your 1099-R Tax Form
2
U.S. Office of Personnel Management. Tax Information for Annuitants
3
Internal Revenue Service. Publication 721, Tax Guide to U.S. Civil Service Retirement Benefits
4
Internal Revenue Service. 2025 Instructions for Forms 1099-R and 5498
5
Internal Revenue Service. Publication 575, Pension and Annuity Income
6
Office of the Law Revision Counsel. 26 USC 72 – Annuities; Certain Proceeds of Endowment and Life Insurance Contracts
7
U.S. Office of Personnel Management. FAQs About Taxes and Federal Retirement
8
Internal Revenue Service. Publication 907, Tax Highlights for Persons With Disabilities
9
Internal Revenue Service. Publication 939, General Rule for Pensions and Annuities
10
U.S. Office of Personnel Management. Request Your 1099-R by Email
11
Internal Revenue Service. What to Do When a W-2 or Form 1099 Is Missing or Incorrect