PowerShell - Bulk Clear-ADAccountExpiration

Error Message: Cannot Validate argument on parameter 'Identify'. The argument is null. 
Csv file
samAccountName
Tst_Posh1
Tst_Posh2
Import-Module ActiveDirectory
$count = 0
$UserId = Import-Csv c:\temp\Clear-Acct-Exp-Date.csv
$out = "Findings   `r`n" #File Heading
ForEach($Item in $UserId)
{
$count++
Clear-ADAccountExpiration -Identity $Item.samAccountName
Write-Host $Item.samAccountName ":" $count
$Out += $Item.samAccountName + ":" + $count + "   `r`n"

}
$out | Out-File c:\temp\Clear-Acct-Exp-Date.txt 
        

mamadukes