The Thrift Savings Plan’s F Fund was built to do one specific job: offer investors a little more return than the ultra-safe G Fund, in exchange for taking on a little more risk. Whether it’s actually delivering on that promise right now depends heavily on which stretch of time you’re looking at.
What the F Fund Actually Holds
The F Fund tracks the Bloomberg U.S. Aggregate Bond Index, split roughly into thirds: investment-grade corporate bonds, mortgage-backed securities, and U.S. Treasuries. Unlike the G Fund, which resets its interest rate monthly and has never posted a losing year, the F Fund’s value moves with the bond market itself. That means it carries real interest rate risk. When rates rise, existing bond prices fall, and the F Fund feels it.
The Long-Term Case
Since inception, the G Fund has returned a little over 5% annualized, while the F Fund has returned better than 6%. That gap compounds significantly over decades: a dollar invested in the G Fund since the late 1980s would be worth roughly double today after inflation, while a dollar in the F Fund would be worth closer to triple. Historically, the F Fund has also outperformed the G Fund in the majority of individual years, not just on average.
Why It Hasn’t Felt That Way Lately
Recent numbers tell a different story. As rates climbed over the past several years, the F Fund posted losses in multiple calendar years, something the G Fund has never done. Looking at trailing returns through mid-2026, the F Fund is roughly flat year-to-date and has lagged the G Fund over the 1-year, 3-year, and 5-year windows, an unusual stretch historically, since the F Fund tends to win more years than it loses.
What This Means for Your Allocation
None of this makes the F Fund a bad choice; it makes it a different risk than the G Fund, not a safer version of it. The two funds serve different purposes inside a diversified portfolio, and neither should be judged on a single year’s return. The better question isn’t “which fund performed better recently,” but whether your current mix still matches your time horizon and how much short-term movement you can tolerate before retirement.
Every federal employee’s situation is different, and a TSP allocation that works well for one person’s timeline may not fit another’s. Speaking with a Federal Retirement Consultant (FRC®) can help you take a closer look at your current mix and whether it still lines up with your retirement goals.
