I switched the majority of my 401k contributions to index funds today. Currently I contribute 20% of my income, some days I want to contribute less so I can build up more liquid savings but I'm earning more money at work now so it should balance out. Anyways, below is my current contribution amount and the expense ratio for each fund. There's not much reason behind choosing the percentages. I wanted a little in bonds to smooth out the volatility and I wanted some international exposure. 10% Bond and Mortgage Fund ( .71% Expense Ratio) 40% S&P 500 Index Fund (.18%) 20% S&P 400 Index Fund (.35%) 20% S&P 600 Index Fund (.35%) 10% International Equity Fund (.86%) That's all for now, if I can come up with a logical reason to adjust the contribution percentages I'll let you know.