After a volatile start to 2026, May TSP performance delivered for investors. Every fund in the Thrift Savings Plan finished the month in positive territory, extending what has quietly become one of the stronger starts to a year in recent memory.
May TSP Performance by Fund
| Fund | May 2026 | YTD 2026 | 12-Month |
| G Fund | +0.39% | +1.80% | +4.40% |
| F Fund | +0.33% | +0.49% | +5.16% |
| C Fund | +5.26% | +11.26% | +29.76% |
| S Fund | +4.49% | +13.48% | +30.48% |
| I Fund | +4.90% | +16.56% | +34.93% |
| L Income | +1.66% | +4.93% | +11.48% |
What Drove the Gains
The broader market shrugged off political and economic uncertainty and focused on fundamentals. The S&P 500 hit a new all-time high on May 1st and built on that strength throughout most of the month, driven largely by a strong corporate earnings season. Approximately 78% of S&P 500 companies beat first-quarter earnings estimates, well above the ten-year average of 74%. That earnings momentum was the primary fuel for the C Fund’s 5.26% gain, its sixth-best May return in the fund’s 38-year history.
The I Fund Leads the Year
The story of 2026 so far belongs to the I Fund. At 16.56% year to date, it leads every other TSP option by a meaningful margin. Two forces are driving that performance: solid international equity markets and a weakening U.S. dollar. When the dollar falls, overseas gains convert back into more dollars, amplifying returns for TSP investors. The I Fund’s 4.90% May return was its fourth-best May on record.
For context, the S Fund leads the C Fund year to date at 13.48% versus 11.26%, a gap built primarily in earlier months of the year.
Where Things Stand
The average TSP account balance for FERS participants stood at $226,251 as of April 30, 2026 — a figure that does not yet reflect May’s strong gains. With the core stock funds up between 4.49% and 5.26% for the month, current balances are likely meaningfully higher.
Looking Ahead
The conditions that produced the strong May TSP performance are not guaranteed to persist. Inflation remains above 3%, the Federal Reserve has signaled it is in no hurry to cut rates, and the ongoing conflict in Iran continues to apply pressure to energy markets and supply chains. Stock prices are reflecting an optimistic scenario — any deterioration in those conditions could prompt a pullback. For federal employees approaching retirement, May TSP performance is a reminder of why having a clear TSP withdrawal strategy matters before you separate from service.
A Federal Retirement Consultant (FRC®) can help you think through how your TSP fits into your broader retirement income picture. Schedule your complimentary benefits review today.