We are still filling up our emergency fund to a minimum of six months of expenses. Bare minimum monthly expenses in our household are $2,500, or $15,000 for six months (normal monthly expenses are $4,000). However, we would like to build up to $20,000 as that is the maximum tier in our reward credit union account, yielding 1.25%. This account is designed to hold only emergency fund. Basically, it is our emergency fund account and that is its sole purpose. We should be very disciplined about not raiding it, unless it is actually an emergency situation.
Separately, we will increase our cushion on our main checking account with Charles Schwab, currently yielding 0.50%. We will use this main checking account to pay all bills and continue to overpay the mortgage when this same account has sufficiently extra funds.