How do I get the amount of the taxable IRA distribution reduced to account for post-tax contributions?

[lsakai]

Post-tax contributions represent about 4% of my traditional IRA accounts.  Note:  I did not file form 8606 in 2016 because I made no IRA contributions in 2016; however, I did previously file form 8606 for 2015.

[fanfare · Accepted solution]

Get out that last Form 8606.

TurboTax will ask you if you have a basis from prior years i.e nondeductible contributions..

Follow the prompts from that point and a 2016 Form 8606 will be attached to your tax return.