"There are basic questions that can help you narrow the field," said Janet Yang, director of multi-asset strategies for research firm Morningstar, which rates target-date funds based on a variety of criteria.
For starters, she said, you can choose between passively managed or actively managed. While all target-date funds invest in underlying assets, passive target-date funds invest in index funds; active funds invest in funds that have professional stock pickers at their helm.
There are a few reasons why active vs. passive can matter, industry experts say.
Passive funds come with lower fees because they basically invest in index funds, which mirror the performance of an index, so a human stock picker is not being paid for expertise.
"Passive is always cheaper," said Kevin Couper, a CFP and financial advisor with Sontag Advisory. "But you have to weigh that lower fee versus what you're getting. … Passive funds might be a little more volatile because you're riding along with the [performance] of the stock market."