Where/when does TT-Deluxe calculate Taxable Amount of 1099-R income via Simplified Method (since some of my income in NOT taxable and my box 2a says "unknown")?

[IsabellaG]

After you enter your 1099-R, as you proceed with the screens, you'll be asked if 2017 was the first year that you received the payments. If you answer no, enter that a different amount was used other than box 2a. Then specify that you used the Simplified Method.

If this is the first year of the distribution, check yes to that question. Then check whether you want to figure out how much is taxable or enter the taxable amount yourself. If you choose to figure the taxable amount with TurboTax, you'll enter the information about start date, plan cost, your age when you began receiving payments, etc. Upon completion, you'll see the screen as to which method was used.

If your annuity start date is after November 18, 1996, you must use the Simplified Method for annuity payments from a qualified plan. Nonqualified plans(and certain annuitants age 75 or over) must use the General Rule.

[dewjow]

Turbo TaxIsabellaG, EA  I understand your explanation.  However, TT recommended that I use TT-DELUXE which is not giving me the screens to follow your suggestion to "enter that a different amount was used other than box 2a. Then specify that you used the Simplified Method."
Are you using/referring to TT-DELUXE or another version of TT?

[IsabellaG]

Yes, all my screenshots came from TurboTax Deluxe Online. If you aren't seeing these screens, I recommend deleting your 1099-R and re-entering it from scratch.

[macuser_22]

The only payer that always puts "UNKNOWN" in box 2a is OPM so I assume that this is a CSA 1099-R.

Be sure to pick the correct 1099-R type:  Standard 1099-R, CSA-1099-R, CSF-1099-R, RRB-1099-R.

The boxes and the interview are different for a CSA 1099-R.