<prompt> Human: I have an old 401k at a company I left 2 years ago, and I like what funds Ive invested in. My new company I just joined has a 401k that Id like to start contributing to. Can I leave my old 401k alone and have 2 401ks? Is it bad interest-wise to split accounts? Thanks!  <response>: Mathematically, it doesnt matter if its in 1 account or 20 assuming the same funds. As long as there is no maintenance fee or anything for the old one, theres nothing wrong with keeping the old 401k 