The mortgage payment on your house will still be due even after you file bankruptcy.
The common misconception people have is if they file bankruptcy, they can keep their house without making the mortgage payment. That's half right and half worng.
When filling for bankruptcy, you can keep your house, as long as you continue to make the mortgage payments.
While in bankruptcy your house is protected, however, if you get behind on the mortgage payment while in bankruptcy, the bank will repossess your house as soon as you emerge from bankruptcy.
Banks often have the paperwork filed and are ready to repossess your house as soon as a person emerges from bankruptcy.
The best time to try to negotiate with the bank regarding your mortgage is when you first realize you will be unable to make a payment. Once someone has filed for bankruptcy or once repossession of the house has begun, it's usually too late for any negotiations.