Yes, if you are eligible to take money out of the Thrift Savings Plan. The TSP itself only offers its own funds - it has no option to hold physical gold or silver. To own metal in a tax-advantaged account, you move TSP money into a self-directed IRA whose custodian holds IRS-eligible precious metals in an approved depository. That is what people mean by a "gold IRA" (see what is a gold IRA).
Traditional TSP money goes to a traditional IRA; Roth TSP money would go to a Roth IRA. Keeping the two separate preserves their tax treatment.



