In this blog, I will show you how to add users to Active Directory security groups using PowerShell, Adding user to any group in an active directory is a very simple task. Either you can right-click on the user and add it to the group or directly you can go on the group and add members.
Adding a single user in a group with PowerShell:
Add-ADGroupMember -Identity infra_ops -Members eng1 On the Above Poweshell command, infra_ops is the group name and eng1 is the user name which we are adding.
Adding Multiple Users in a group (infra_ops)
Create a CSV file with all users list and save it in the same location from where this will be called in a variable, In the below example this is called in $user.

Run the below PowerShell command
Import-Module ActiveDirectory
# Import the data from CSV file and assign it to variable
$Users = Import-Csv "C:\ad_data\infra_ops.csv"
# Specify target group where the users will be added to
$Group = "infra_ops" 
foreach ($User in $Users) {
    # Retrieve UPN
    $UPN = $User.UserPrincipalName
    # Retrieve UPN related SamAccountName
    $ADUser = Get-ADUser -Filter "UserPrincipalName -eq '$UPN'" | Select-Object SamAccountName
    # User from CSV not in AD
    if ($ADUser -eq $null) {
        Write-Host "$UPN does not exist in AD" -ForegroundColor Red
    }
    else {
        # Retrieve AD user group membership
        $ExistingGroups = Get-ADPrincipalGroupMembership $ADUser.SamAccountName | Select-Object Name
        # User already member of group
        if ($ExistingGroups.Name -eq $Group) {
            Write-Host "$UPN already exists in $Group" -ForeGroundColor Yellow
        }
        else {
            # Add user to group
            Add-ADGroupMember -Identity $Group -Members $ADUser.SamAccountName -WhatIf
            Write-Host "Added $UPN to $Group" -ForeGroundColor Green
        }
    }
}