They may or may not take all of it depending on how much they paid you per month and how much SSDI pays you per month. I had to pay back almost all of my backpay received for me. I did have a little left over but can't remember exactly how much. Do you have children? I have two children and also received money for them but was able to keep all of their backpay.

I Wasn't crazy about re-paying them but since my private disability carrier did pay me every month while I waited for approval and the contract stated that I would have to repay them, it was the right thing to do. Plus I was grateful that I did have some income coming in the household for me while I waited so long for SSDI approval.