Roth basis

What do you think about this translation?

You will have to determine whether contributing to your plan on an after-tax Roth basis or a traditional before-tax basis makes more sense for your situation.

Usted deberá determinar si desea realizar los aportes a su plan mediante el sistema Roth, por el cual los impuestos se deducen al momento de hacer los aportes, o si prefiere el sistema tradicional por el cual los impuestos se deducen al momento de retirar los aportes.

Any suggestions?

Your translation seems to go beyond the original in terms of clarifications, but there's nothing wrong with that if it's based on your mastery of the subject. Not being qualified to certify whether your "extensions" are technically correct, your translation looks very good to me.

Wonderful! thanks for the info that you guys have been discussing. Awesome!!!!