G Fund Opportunity Cost

Select your enrollment year and comparison fund to see the exact dollar gap between your G Fund trajectory and a C or S Fund alternative — calculated from real TSP.gov price history.

Rank

Years of service

TSP enrollment year

Contribution %

I'm on BRS (adds DoD 1% auto + up to 4% match)

Projected TSP withdrawal year

Projects balances forward using avg historical returns. Penalty-free TSP withdrawal begins at age 59½.

20-yr military retirement: ~2040

TSP penalty-free withdrawal: age 59½ — military retirement at 38 does not waive the early withdrawal penalty

Total contributions

$13,172

G Fund balance today

$14,493

C Fund balance today

$19,490

Performance gap today

$4,998

Comparison outperformed G Fund

G Fund at 2051projected

$93,487

C Fund at 2051projected

$1,654,908

$1,561,421 ahead of G Fund

Over this period, C Fund returned ~16.3% vs G Fund's ~3.1% annually. Members who defaulted into the G Fund missed this difference.

Change your TSP allocation at tsp.gov

Compare G Fund against

Dashed vertical line marks end of historical data (2025). Values to the right are projected. Contributions stop at projected military retirement (2040).

Historical results only — not a forecast. Projected values use avg historical returns (3.1% G / 16.3% C Fund) and do not account for future market changes. Past performance does not predict future returns. To change your TSP fund allocation, visit tsp.gov.

Authority: Thrift Savings Plan (TSP)

Why the G Fund has an opportunity cost

Auto-enrolled BRS members start in an age-appropriate Lifecycle (L) fund, but many never change their allocation and end up effectively in the G Fund over time. It is government-backed, never loses nominal value, and earns a rate tied to intermediate and long-term Treasury yields. That safety comes with a cost: over most multi-year windows, equity funds (C Fund — S&P 500 index; S Fund — small/mid-cap index) have produced materially higher nominal returns.

This calculator computes the dollar gap between what your TSP balance would be today if you had contributed to the G Fund since your enrollment year versus the same contributions invested in a C Fund, S Fund, or 60/40 C+S blend. Returns are sourced directly from TSP.gov annual fund price history. Pay-based contribution amounts use DFAS 2026 basic pay tables adjusted for your rank and estimated years of service at enrollment.

The result is an estimate, not a guarantee of future performance. TSP fund returns vary year to year; the G Fund outperforms equity funds in down-market years (2022 being a clear recent example). Over longer windows — especially those including 2019–2021 and 2023–2024 — equity exposure has historically produced substantially larger balances. The decision to reallocate is yours; this tool gives you the number to make that decision with.

Authority: TSP.gov — Investment Options · TSP.gov fund price history · DFAS 2026 pay tables

Why the G Fund has an opportunity cost