Multiple Accounts

I manage the Centering program for my agency which involves four different sites. When I login to CenteringCounts I only have access to one of our practice sites. Is it possible for me to have access to multiple practices on Centering Counts?
In order to set this up, can I be given an account for another site to get them started and then add their staff members to it or does another member of that team need to be given the account and add me as a staff member?

Thanks!