If you’d like to know when someone in Teams changes their status to Available or Offline, you can add them to your status notifications list either through a previous chat or in settings. 

Note: You can add up to 15 people to your status notifications list.

After you add someone to your status notifications list, you’ll see a desktop notification banner at the bottom of your screen along with a notification in action center (if turned on in settings) whenever their status changes. 

Status notification banner

The chat option is convenient if you've recently had a one-on-one chat with the person that you want to get notifications about. 

Choose Chat on the left side of the app.

In your chat list, choose a one-on-one chat that includes the person that you want to be notified about.

Select More options and then choose Notify when available.

To stop seeing a person's status, follow the previous steps, and then choose  Turn off notifications.

The settings option allows you to search for someone in your organization and then add them directly to your notifications list.

Select your profile picture in the top right of Teams. Next, select   Settings >  Notifications to open notification settings.

Select the Edit button to the right of People to open the manage status notifications screen.

In the manage status notifications screen, type the name of the person that you want to be notified about in the Add people search box. Select their name when it appears.

To remove someone from your status notifications list, follow the previous steps and then select the Turn off button next to their name.