For billing "excluded" Cost Centers", the client medicaid number will be used if it is entered. If the Medicaid Number has not been entered, then the Social Security number will be used. And If that hasn't been entered, then the Payroll ID (PID) will be used.
Since the transmission file expects 12 digits for the Medicaid Number field, it will be padded with 0's where the number is less than 12. For example, if the PID number is 1489, then the Medicaid Number field in the Transmission Flat File will be 000000001489.
Remember, the excluded Cost Center must be selected in the Cost Center filter on the billing screen when creating the invoice.