Not at present. The TSP has had authority since 2009 to create an investment “window” through which participants could invest in outside funds. For a number of years that authority was low priority but more recently the governing board of the program has started looking into the idea more seriously.
In mid-2015 the TSP committed to using that authority, although the option was projected to be in place no earlier than late 2016. Funds are to be available through a mutual fund company under contract with the TSP, but details remained to be determined, including investment minimums and maximums and additional fees to be charged to those who make outside investments.
Including the time needed to issue such a contract, make needed changes to systems and conduct an educational campaign, it is not expected to be in place until late 2016 at least.