Used Roth towards first home. Roth < 5 yrs old. 1099-R says 'taxable amount not determ..how does one ensure earnings from a Roth IRA are given proper tax treatment?

[dmertz]

Since you said that you have had a Roth IRA less than 5 years (your first contribution to a Roth IRA was for 2014 or later), Roth earnings (up to $10,000) used for a first-home purchase are taxable but not subject to early-distribution penalty.  Assuming that you were under age 59½ at the time of the distribution, after entering the code J Form 1099-R and answering the immediate follow-up questions, click the Continue button on the Your 1099-R Entries page, enter your basis in Roth IRA contributions and conversions, then on the Did you use your IRA to pay for any of these expenses page, enter in the First home purchase box  the amount of the distribution that would otherwise be subject to penalty.

(If you meant to say that you had a Roth IRA more than 5 years, just indicate in the immediate follow-up that the money was used to purchase a first home.)