You generally cannot buy physical gold in your 401(k) as you could with a gold IRA. You may be able to buy assets that invest in gold, though. Your 401(k) may offer investment options, such as a mutual fund, that track precious metals including gold. That said, investing in a 401(k) is limited to the investment options your particular plan offers. If a gold-based investment is not included, you won’t be able to invest in gold-based assets within your 401(k).