If you bought a house with your sister, you are both responsible for the loan separately and together.  This means you are each required or obligated to pay the full amount to the lender/servicer.  You need to talk with your servicer and see if you can apply for a modification, forebearance or something else entirely but both of you will have to be on that modification sheet. Talk to the servicer. Perhaps your sister can quitclaim her title to you so that you can pursue a full refinance. Before you do anything, however, talk to the servicer first.