AD required to manage RDS?

I have a need for a small server that can run RDS for a medical office with 4 client computers.  Can a single Win2012r2 server with RDS run in this environment without having to also add a Domain Controller?  For so few resources to manage I was hoping to be able to just install a simple Windows server with RDS and the application and a printer and not need to virtualize or deal with a domain controller at all.  But I cannot find info on whether this is even possible.  Thanks