Determine your time horizon, or how many years you'll have before you need to start withdrawing money from your TSP account. For example, if you are 35 years old today and you don't expect to start withdrawing from your TSP account until you are 65 years old, your time horizon is 30 years.

If you have a longer time horizon, you may want to take more risk in your TSP account. Remember, your TSP account will need to provide income for you throughout all of your retirement years.