I frequently see 401(k) and 403(b) plans with a hundred investment options, and they are proud of the flexibility they offer participants.
If you are in a plan like that, I’m sorry.
That breadth doesn’t benefit you. It benefits the fund managers. They are hoping you’ll be tempted into picking a lot of narrow funds (“emerging markets high yield bond fund”, “biotechnology sector fund”, etc.) with higher than average fees. Don’t fall for it.
Instead, find the broadest, lowest-fee funds, and use no more than four to construct a diversified portfolio. The best combination is usually a bond fund, a US stock fund and a non-US stock fund. Even better, if your 401(k) offers it at a reasonable price, is a “target date” fund. This fund owns a global mix of stocks and bonds and adjusts, over time, as you age. It solves the problem that many people don’t adjust their 401(k) for years, so it can get out of balance. If you don’t manage it periodically, it also won’t reflect the fact that, as you age, you are likely to want a more conservative mix of investments.
A lot of choice is great if you’re shopping for shirts. In investing, it’s an invitation to transfer wealth to Wall Street. Really, you need the money more than they do.