You don’t even need to use multiple banks. Each individual amount is insured to $250k. So if you have monthly payroll due of $1M, then open four checking accounts (all at the same bank), and don’t keep more than $250k in each.
> Deposits are insured up to at least $250,000 per depositor, per FDIC-insured bank, per ownership category.
https://www.fdic.gov/resources/deposit-insurance/faq/index.h...
> Coverage Limit: All deposits owned by a corporation, partnership, or unincorporated association at the same bank are added together and insured up to $250,000, separately from the personal accounts of the owners or members.
> The corporation, partnership, or unincorporated association must be separately organized under state law and operate primarily for some purpose other than to increase deposit insurance coverage.~
https://www.fdic.gov/resources/deposit-insurance/financial-p...