OPM CSA 1099 has "unknown" for the taxable income. How do I determine the taxable dollar amount?

pmshaw559 — Sat, 07 Feb 2026 00:34:28 GMT

Re: OPM CSA 1099 has "unknown" for the taxable income. How do I determine the taxable dollar amount?

KrisD15 — Sat, 07 Feb 2026 00:39:22 GMT

Is this the first year you received a CSA 1099-R?

Was this originally your account or was it inherited?

JamesG1 — Wed, 11 Feb 2026 02:48:14 GMT

TurboTax Online will use the simplified method to determine the taxable portion for box 2a of your CSA 1099-R. Presume that:

You will need to know:

Follow these steps:

Down the left side of the screen, click Federal.
Down the left side of the screen, click Wages & Income.
Click on the down arrow to the right of Retirement Plans and Social Security.
Click to the right of IRA 401(k) Pension Plan Withdrawal (1099-R).
At the screen Who gave you a 1099-R, select Office of Personnel Management (CSA 1099-R).
At the screen Annuity information, select Yes for the question Did you get periodic payments from this retirement account on a regular basis?
At the screen Annuity information, select Yes for the question Did you start getting payments in 2025.
At the screen Annuity information, select No for the question For the years you received these distributions, was the total amount shown in the form the amount you paid tax on?
At the screen Annuity information, enter the annuity start date, plan cost, months payments were received and amount recovered in previous years. (This will be $0 if this is the first year that you receive the payment.)
At the screen Annuity Information, Plan Cost should be in box 9b.
At the screen Annuity Information, enter the beneficiary ages.
The taxable amount will be computed by the simplified method.

View Federal 1040 tax return line 5a and 5b at Tax Tools / Tools / View Tax Summary / Preview my 1040.