Effective June 25, 2012 you can make Roth contributions to your TSP account. The Roth feature gives you greater flexibility in the tax treatment of your account. With Roth contributions, you pay taxes now; however, when you withdraw these contributions they are tax free. Roth earnings are also tax-free as long as you are 59½ or older and you have had Roth contributions for five years or more when you receive your distribution.