Vanguard has protections through SIPC and additional underwriters that provide ample security, comparable to FDIC. The return on a MM at VG (or Fidelity for that matter) will generally be better than unsubsidized MMs at most banks or credit unions. Having said that, if you are willing to work for it you can probably do marginally better with some of the options already suggested, in addition to chasing bank sign up bonuses and the like. For set it and forget it without any strings attached VG is hard to beat. The biggest return would come from capturing the state tax deduction for a 529, as already suggested, especially if your state allows carry forward. But that assumes you get a state tax deduction in your state. Also be mindful of effects on AOTC if you’re eligible.