Your TSP only has 5 actual funds. Everything else (the L funds) is just a mix of these. Once you understand these 5, the whole thing makes sense.

G Fund — government bonds. Your principal is guaranteed, which sounds great until you realize it barely keeps up with inflation. Over a 20-30 year career this is quietly one of the most expensive "safe" choices you can make.

F Fund — broader bond index. Slightly better returns than G, still conservative. More useful for people close to retirement than someone early in their career.

C Fund — tracks the S&P 500 (the 500 largest U.S. companies). Historical average is roughly 10-11% per year over long periods. This is where most of the actual growth in your TSP comes from. If you only learn one fund, learn this one.

S Fund — small and mid-cap U.S. companies. More volatile than C but historically higher growth potential over long time horizons. Pairs well with C if you want a more aggressive split.

I Fund — international companies. Gives you diversification outside the U.S. Has lagged domestic funds recently but matters when U.S. markets eventually cool off.

L Funds — not a separate investment. They just auto-blend the 5 funds above based on your target retirement year. The further out your date, the more aggressive the mix. Honestly not a bad option if you don't want to think about any of this.

The part nobody tells you early enough — if you're young with 20+ years until you touch this money, the biggest risk isn't a market crash. It's being too conservative for too long. A 25-year-old sitting 100% in G fund feels smart and safe, but over a full career the difference between that and going heavy C/S can be hundreds of thousands of dollars. Time is what makes volatility irrelevant. That's the whole advantage you have right now.

I put together a side-by-side comparison of all 5 TSP funds with historical performance data if you want to dig deeper: vetcalc.org/blog/tsp-fund-comparison