Migrate users to island mode in Teams.

Microsoft Teams Powershell module is very limited so we will use Skype for Business Online. You can download the module below:

https://www.microsoft.com/en-us/download/details.aspx?id=39366

Once downloaded open PowerShell run the following commands to connect:

Import-Module SkypeOnlineConnector 
$sfbSession = New-CsOnlineSession 
Import-PSSession $sfbSession

Note: Use global admin credentials to avoid bottlenecks.

Once connected run this command to change all users to island mode on Microsoft Teams:

$users = Get-CsOnlineUser

foreach ($core in $users){
write-host "To Teams: "$core.UserPrincipalName
Grant-CsTeamsUpgradePolicy -Identity $core.UserPrincipalName -PolicyName IslandswithNotify
}

Note: You may replace SfBOnly for Skype for Business only mode or UpgradeToTeams to move to Teams only mode.

You can run this command to check the status of your users:

Get-CSOnlineUser | select UserPrincipalName, teamsupgrade*

You can get a report on existing TeamsUpgradePolicy users (CSV Report):

$objUsers = Get-CSOnlineUser | select UserPrincipalName, teamsupgrade* 
$objusers | ConvertTo-Csv -NoTypeInformation | Out-File "$env:USERPROFILE\desktop\TeamsUpgrade.csv"

Note: This will create a CSV file on the Desktop of the current user with the name "TeamsUpgrade.csv"