To effectively manage a federal client’s retirement portfolio, financial professionals must understand the mechanics, underlying indices, and strategic roles of the five core TSP funds.
3 TSP Allocation Options for Federal Workers
The Thrift Savings Plan is the federal government’s version of a 401(k), and for most federal employees, it represents the largest source of long‑term retirement wealth outside of their FERS pension. The TSP offers three broad investment avenues: the Lifecycle (L) funds, the Mutual Fund Window, and the five individual core funds. While the L Funds provide a simple, target‑date approach, they are composed of the five main options and may be too conservative or too risky, depending on which L Fund an employee is invested in. The Mutual Fund Window opens the door to thousands of outside funds, the significantly higher fees can erode long‑term returns, especially if investors trade too much or treat it as a “set it and forget it” investment.
By understanding the structure and behavior of the five core funds, financial professionals can design portfolios that align with a client’s risk tolerance, retirement timeline, and income needs. Combined with an outside account like an IRA, the TSP can supercharge retirement income for federal employees.
Fixed Income and Capital Preservation: The F and G Funds
For employees nearing retirement or those with a lower risk tolerance, some assume the G and F Funds provide a relatively safe haven for cash to grow a modest amount, or do they…
Government Securities: The G Fund
The G Fund is completely unique in the investment world. It grows according to the interest rate of U.S. Treasury securities issued exclusively to the TSP, and by law, the fund can never post a negative return. But because of this, the return rate rarely gets over 5% (the last time it was that high being 2001), and in fact has a 10-year average of 2.87% (as of 5/2026). The monthly return of the G Fund is also what the TSP uses to determine the interest rate for loans.
The 2 main risks involved is inflation and IOUs. Inflation can quietly erode purchasing power over a 20‑ to 30‑year retirement. But the government IOUs are a bit more of an immediate concern. You see when the national budget debt ceiling is hit, then the government issues IOUs for interest. If this is not a concern for the employee, then it could be considered a safe harbor for savings. Therefore, advisors must caution clients against shifting entirely into the G Fund as they approach retirement. Especially, since some savings accounts and certificate deposits outside of the TSP have been more competitive in recent history. If the employee is able to make in-service withdrawals, there are usually better financial solutions for feds, such as an annuity or managed portfolio.
Many feds “move everything to G” when markets experience an increased volatility. This can be especially damaging to their future retirement situation because by the time they’ve bought back in, they’ve missed out on significant gains.
The F Fund: Fixed Income Investment Index
The F Fund provides a more traditional fixed‑income opportunity. It tracks the Bloomberg U.S. Aggregate Bond Index and includes a diversified mix of investment‑grade bonds. While it carries modest volatility compared to the G Fund, it offers broader fixed‑income exposure and some think this index can serve as a stabilizing force during equity downturns.
Equity funds provide have been known to provide more opportunity for growth but that comes with market risk. This funds 10 year average is lower than the G Fund siting at 1.79% (as of 5/2026).
Schedule a meeting now to learn how Fed Options can help take your financial firm or agency to the next level when it comes to helping federal employees plan for retirement.
VIEW CALENDARThe Growth Engines: C, S, I Funds for Equity Investments
To outpace inflation and build long‑term wealth, advisors should incorporate the C, S, and I Funds, representing the equity side of the TSP. Without completely understanding the indices that each one tracks, though, you can end up leaving your client’s investment strategy vulnerable to preventable losses, especially if unmanaged.
The C Fund: US Domestic Large Cap Stocks
The C Fund tracks the S&P 500 and represents large‑cap U.S. companies. It is often the primary growth engine of a TSP portfolio, delivering strong long‑term returns with moderate volatility. For many federal employees, the C Fund is the anchor of their allocation with exposure to domestic common stocks from companies with a large market cap.
The S Fund: Small and Medium US Stocks
The S Fund expands that exposure by tracking the Dow Jones U.S. Completion Total Stock Market Index, which includes small‑ and mid‑cap companies not found in the S&P 500. It includes stocks from around 4500 US companies. This fund historically delivers higher growth potential but also experiences the largest swings and deepest drawdowns. It doesn’t behave like a true small cap fund, though, so it is important not to be misled by the “S” in S fund.
The I fund: New Facelift for International Equities
The I Fund rounds out the equity lineup by tracking the MSCI ACWI IMI ex USA ex China ex Hong Kong Index. This provides exposure to developed and emerging markets outside the United States, offering essential geographic diversification. While international markets can behave unpredictably and some political risk, the I Fund helps reduce home‑country bias and broaden long‑term opportunity. The biggest criticism against the I fund historically used its index. In 2024, however, the TSP gradually shifted from the old index to the aforementioned one. While it excludes China and Hong Kong, it includes a lot more countries than it did before and, unlike its predecessor, does invest in emerging markets.
Together, the C, S, and I Funds form the best opportunities for growth, and understanding how they operate, including the risks associated with each, can boost portfolios over a long stretch of time.
Help Feds Get the Most Out of their TSP
Educating federal employees on the distinct roles of the G, F, C, S, and I Funds is one of the most impactful services an advisor can provide. Misunderstanding these options can lead to portfolios that are either too aggressive near retirement or too conservative to sustain long‑term financial security. Advisors who know the TSP’s core funds inside and out can build portfolios that are efficient, intentional, and aligned with each client’s unique retirement trajectory.
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