Troubleshooting

Hello,
I came onto this thread because I wasn’t able to transfer my son’s full $5000 amount over to us.  I have followed the instructions from the link which you have posted in order to reach the page indicating the “maximum amount available to transfer”.   My son does not need the current year’s tuition to help bring his tax liability to $0 as he is already getting a refund.  His tuition amount for the current year is above $5000, so my understanding is that he would be able to transfer that full amount to us and any remaining will be carried for him to use in future years. But Turbotax is showing an amount of $3048.66 not $5000.  I don’t understand how it arrived at that number?