Because it is a Roth and not a Traditional IRA. Only Traditional IRA contributions are deductible. Roth IRA's are always after-tax money which means that you will not pay tax when you take the money out, since you already paid the tax. With a Traditional IRA the money is taxed when you take it out.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
