You can think of groups as 'active care lists'. For example, if you have created a hospital visit group then all the people in that group should be in the hospital. That being said, you are going to be adding and removing people from groups.
Removing a person from a group will not delete any existing updates, tasks and milestones.
Removing People From Groups
Click on the the person's name you want to remove from a group
Click the 'x' next to the group you want to remove them from. The group(s) can be found directly under the person's name.
