You could be missing out on hundreds of thousands of dollars, when switching wouldn't cost you a cent.
Those default accounts were never meant to be permanent, and the providers are supposed to help you decide what to do next, and what type of fund is best for you.
But in the year to March 31, 2017, 16,902 people switched out of their default fund and into a better one. That's way down from the 28,608 the year before.
Now the FMA says that has to change. They want the default providers to explain what's going on, and come up with a plan to do better.
But hey, why wait for them to get their act together when there's plenty we can do ourselves?
I called AUT Professor of Finance Bart Frijns, to pick his brains on what people can do to make their KiwiSaver better.
We talked about how what type of fund you're in matters more than how much money you put into it, and what providers can do to look after their customers better. For the interview, listen to the podcast.
If you have a question about this podcast, or something you want me to look into for next time, come and talk to me about it. I'm on Facebook here and Twitter here.
Don't forget to hit subscribe on either Apple podcasts or I Heart Radio to make sure you never miss a trick with your money.