I think we're getting hung up on words, and all saying the same thing. The contribution isn't taxed - it has already been taxed as income as part of your paycheck or whatever. You're contributing after tax dollars to a Roth plan (401k or IRA) and that money grows tax free. Additionally, you can do funky stuff (if you choose), like withdraw the principal at a later date, and not pay any tax on it. Your gains and interest cannot be withdrawn until 59 1/2 (I think) or may be withdrawn for a qualifying event (like buying a first home, for example). The shitty part is you can only contribute $5500 a year, unless you do some tax gymnastics to convert a regular IRA to a Roth (and it often doesn't work out in your favor unless someone knows what they're doing).