Technically, a IRA conversion is from a non-Roth IRA account into a Roth IRA account, often with a taxable impact.  Because it was a TSP, it can be treated as a rollover and this amount will be added to your taxable income for the year. Since it is a rollover, the annual limit for contributions do not apply.

Thanx, MaryK.  I'm paying the taxes this year on it....  Ouch now, less ouch later.  Just want to be covered a few years down the line when I attempt to withdraw it tax-free.  Is there a form or an entry in TT that I will need or use should there be questions? My brokers inferred they would mark something on the 2020 1099R if it were broker to broker.  I suppose I can just make a note of it a see what happens.  Just don't want to miss the checkmark that TT provided....if there is one.

Yes, TurboTax will ask you in the interview the questions needed to calculate the tax, indicate the rollover- this will also adjust the amount of penalty for early withdrawal.  Your 1099-R should have a Box 7 Code 1.  Please post again if you have questions while entering!

@jc_penny