Administrators can create new user roles in ClockwiseMD from Settings. Here are the screens that can are authorized for each of the Universal Roles:

To add a new role, navigate to:

Users and Security > Users > Roles > New

From here, choose a name for the new role, and click which screens should be authorized. For example, I want a user that can only access the Nurse Screen, so I have named my new role "Nurse Screen Only" and clicked only the box next to Nurse Screen.

Don't forget to click "Create Role" to save your work. 

After you create your new user role, you can edit the roles of existing users or add new users with this role as it will appear in the drop-down list of available user roles. (See article about Adding Users)