While in a chapter 13, you need to stay current on the chapter13 plan payments as well as the mortgage payments (if you are paying your post-filing mortgage payments directly).
If you are behind on direct payments, you have 3 options with the mortgage.
1. catch up. if you cannot cure by the motion date, you can tender what you have, and ask for a short continuance to get the rest.
2. If you cannot, you can tender as much as you can, then see if they are willing to enter into what is called a default repayment agreement, whereby they elect to take a repayment plan
in addition to the regular payments (usually between 2-6 months). You agree to let them modify the stay if you fail to keep up with these payments as agreed.
(This does not apply if the trustee
sends the lender the current payment from your trustee payment)
3. You can let the stay modify and deal with the lender outside of the case (loan modification
, refinance etc)
4. Conversion to chapter 7may be an option too, talk to your lawyer to see if you qualify.