If you invest in Vanguard Treasury Money Market (VMPXX) then the $100,000 FDIC limit doesn’t apply. Your insurance is the US Govt. itself for the full amount. In addition to that, you can seek higher yields using TreasuryDirect.gov by buying T-Bill, T-Notes, and I-Series US Savings bonds, as another poster mentioned. If any of these go illiquid, we are all in deep sh**.