diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6022d56b..3867883a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,8 @@ For older change log history see the [historic changelog](HISTORIC_CHANGELOG.md)
 - ADGroup
   - Refactored Module.
   - Refactored Unit and Integration Tests.
+  - Fixed management of child domain user membership.
+    ([issue #633](https://github.com/dsccommunity/ActiveDirectoryDsc/issues/633))
 
 ### Added
 
diff --git a/source/DSCResources/MSFT_ADGroup/MSFT_ADGroup.psm1 b/source/DSCResources/MSFT_ADGroup/MSFT_ADGroup.psm1
index cdc22533..6ea4f410 100644
--- a/source/DSCResources/MSFT_ADGroup/MSFT_ADGroup.psm1
+++ b/source/DSCResources/MSFT_ADGroup/MSFT_ADGroup.psm1
@@ -106,6 +106,7 @@ function Get-TargetResource
 
             if ($_.FullyQualifiedErrorId -eq $oneWayTrustFullyQualifiedErrorId)
             {
+                Write-Debug -Message 'Processing Group Members - One-Way Trust'
                 # Get-ADGroupMember returns property name 'SID' while Get-ADObject returns property name 'ObjectSID'
                 if ($MembershipAttribute -eq 'SID')
                 {
@@ -130,20 +131,51 @@ function Get-TargetResource
                         'ObjectSID'
                     )
 
-                    $adObject = Get-ADObject @getADObjectParameters
+                    $adObject = Get-ADObject @getADObjectParameters -Server :3268
 
-                    # Perform SID translation to a readable name as the SamAccountName if the member is
-                    # of objectClass "foreignSecurityPrincipal"
-                    $classMatchForResolve = $adObject.objectClass -eq 'foreignSecurityPrincipal'
-                    $attributeMatchForResolve = $MembershipAttribute -eq 'SamAccountName'
-
-                    if ($classMatchForResolve -and $attributeMatchForResolve)
+                    if ($adObject.objectClass -eq 'foreignSecurityPrincipal' -and
+                        $MembershipAttribute -eq 'SamAccountName')
                     {
                         Resolve-SamAccountName -ObjectSid $adObject.objectSid
                     }
                     else
                     {
-                        $adObject.$selectProperty
+                        if ($selectProperty -eq 'SamAccountName')
+                        {
+                            $adGroupDomain = ([RegEx]::Matches($adgroup.DistinguishedName, '(?i)DC=\w{1,}?\b') |
+                                ForEach-Object { $_.Value })
+                            $memberDomain = ([RegEx]::Matches($adobject.DistinguishedName, '(?i)DC=\w{1,}?\b') |
+                            ForEach-Object { $_.Value })
+
+                            if ($adGroupDomain -ne $memberDomain)
+                            {
+                                $forestDomains = (Get-ADForest).Domains
+                                foreach ($domain in $forestDomains)
+                                {
+                                    $domainDetails = Get-ADDomain -Identity $domain
+                                    $domainDN = $domainDetails.DistinguishedName
+                                    if ($memberDomain = $domainDN)
+                                    {
+                                        $domainNetBIOSName = (Get-ADDomain -Identity $domainDetails.DNSRoot).NetBIOSName
+                                        break
+                                    }
+                                }
+
+                                if (-not [System.String]::IsNullOrEmpty($domainNetBIOSName))
+                                {
+                                    "$domainNetBIOSName\$($adObject.SamAccountName)"
+                                }
+                                else
+                                {
+                                    $errorMessage = 'Domain $domain not found in Forest'
+                                    New-InvalidResultException -Message $errorMessage
+                                }
+                            }
+                        }
+                        else
+                        {
+                            $adObject.$selectProperty
+                        }
                     }
                 }
             }
@@ -154,6 +186,8 @@ function Get-TargetResource
             }
         }
 
+        Write-Debug -Message "Group Members: $($adGroupMembers -Join ',')"
+
         $targetResource = @{
             Ensure              = 'Present'
             GroupName           = $adGroup.Name
diff --git a/source/Modules/ActiveDirectoryDsc.Common/ActiveDirectoryDsc.Common.psm1 b/source/Modules/ActiveDirectoryDsc.Common/ActiveDirectoryDsc.Common.psm1
index 43cd30a2..ef70c91c 100644
--- a/source/Modules/ActiveDirectoryDsc.Common/ActiveDirectoryDsc.Common.psm1
+++ b/source/Modules/ActiveDirectoryDsc.Common/ActiveDirectoryDsc.Common.psm1
@@ -1117,6 +1117,8 @@ function Set-ADCommonGroupMember
         $Action = 'Add'
     )
 
+    Write-Debug 'Entering Set-ADCommonGroupMember'
+
     Assert-Module -ModuleName ActiveDirectory
 
     $setADGroupParameters = $Parameters.Clone()
@@ -2599,6 +2601,8 @@ function Resolve-MembersSecurityIdentifier
 
     begin
     {
+        Write-Debug 'Entering Resolve-MembersSecurityIdentifier'
+
         Assert-Module -ModuleName ActiveDirectory
 
         $property = 'ObjectSID'
@@ -2643,30 +2647,51 @@ function Resolve-MembersSecurityIdentifier
         {
             if ($MembershipAttribute -eq 'SamAccountName' -and $member -match '\\')
             {
-                Write-Debug -Message ($script:localizedData.TranslatingMembershipAttribute -f
+                $memberDomainName = $member.split('\')[0]
+                $memberSamAccountName = $member.split('\')[1]
+                try
+                {
+                    $memberDomainDetails = Get-ADDomain -Identity $memberDomainName
+                }
+                catch [System.Security.Authentication.AuthenticationException]
+                {
+                    Write-Debug -Message ($script:localizedData.TranslatingMembershipAttribute -f
                     $MembershipAttribute, $member, $property)
 
-                $securityIdentifier = Resolve-SecurityIdentifier -SamAccountName $member
+                    $securityIdentifier = Resolve-SecurityIdentifier -SamAccountName $member
+                    $sid = $true
+                    $memberDomainDetails = $null
+                }
+
+                if ($memberDomainDetails)
+                {
+                    $securityIdentifier = (Get-ADObject -SearchBase $memberDomainDetails.DistinguishedName -Filter "SamAccountName -eq '$memberSamAccountName'" -Server :3268).DistinguishedName
+                    $sid = $false
+                }
             }
             elseif ($MembershipAttribute -eq 'DistinguishedName' -and ($member -split ',')[1] -eq $fspADContainer)
             {
                 Write-Debug -Message ($script:localizedData.ParsingCommonNameFromDN -f $member)
 
                 $securityIdentifier = ($member -split ',')[0] -replace '^CN[=]'
+                $sid=$true
             }
             else
             {
                 Write-Debug -Message ($script:localizedData.ADObjectPropertyLookup -f
                     $property, $MembershipAttribute, $member)
 
-                $getADObjectParms['Filter'] = "$($MembershipAttribute) -eq '$($member)'"
+                #$getADObjectParms['Filter'] = "$($MembershipAttribute) -eq '$($member)'"
+                $getADObjectParms['Identity'] = $member
 
-                $securityIdentifier = [string](Get-ADObject @getADObjectParms).$property
+                #$securityIdentifier = [string](Get-ADObject @getADObjectParms -Server :3268).$property
+                $securityIdentifier = $member
+                $sid=$false
             }
 
             if (-not ([string]::IsNullOrEmpty($securityIdentifier)))
             {
-                if ($PrepareForMembership.IsPresent)
+                if ($PrepareForMembership.IsPresent -and $sid -eq $true)
                 {
                     "<SID=$($securityIdentifier)>"
                 }