I-9s can be sent to payroll along with the rest of a Startwork packet. Currently in TiM, I-9s cannot be sent individually.
Once packets are selected to be sent, and "Send to Payroll" is clicked, a pop-up will appear. Within the pop-up is the option to include I-9s in the batch. De-select if you do not wish to include I-9s in the batch.