Why would I need to track the basis of a Roth IRA? I have not converted any traditional IRA's but I did roll at Roth 401-k into my Roth IRA.

[DDollar · Accepted solution]

The main reason you would want to track Roth IRA contributions is in case you make early withdrawals.  You can take distributions of your Roth basis prior to age 59 & 1/2 without having to pay any tax or penalty (subject to certain restrictions).  If you never take early distributions, and didn't do a conversion, then under current tax law you would never need to know the basis.