Hi:

When you state " how important is it to list total amount of my Roth IRA contributions over all these years? "  I'm assuming you mean in TT?

It's a good way to keep track of your contributions, but not mandatory.

HOWEVER, you DO NEED to keep track of your contributions. Why?  Because if you ever take out funds before 59 1/2 and/or before the funds have been in for 5 years, your withdrawal needs to be split.

Part of the withdrawal would non-taxable as your contribution(s).  The other part would be taxable as earnings on the contribution(s).

Thus, you need to keep track of all your contributions to a Roth IRA.

This would also apply to any non-deductible contributions that were made into a traditional IRA as well.