I made an excess contribution of $6,000 to my Roth IRA in 2014, and TurboTax calculated a tax of $360 (6%) on IRS Form 5329, which I paid. Every year since then, when I imported my prior year return, TurboTax imported that contribution and added another $360 to my total. I only just noticed this. Has anyone else had this experience? I need to amend my returns for 2015, 2016 & 2017. I should have been more vigilant. What a pain.
It's proper that you owe the penalty every year until the excess is corrected, so if you have not corrected the excess, either by obtaining a return of contribution before the due date of your 2014 tax return, by obtaining a regular distribution of the excess after the due date of your 2014 tax return or by being able to apply the excess as part of your Roth IRA contribution for some year after 2014, you have no reason to amend the earlier tax returns and you owe the same penalty again for 2018.
If the excess is still present in your Roth IRAs after considering all of the ways that the excess might already have been corrected, you need to make a regular distribution of $6,000 from the Roth IRA to avoid another penalty for 2019.