I would like to know how I would go about a mortgage? My mom helped me purchase a house due to her good credit and due to her owning other properties she was approved but at a high rate. I have been paying the mortgage straight out of my account and now my fiancé and I are in a better position and would like to assume responsibility of the mortgage at a better rate. I currently hold title to the house and I am on the deed. We would like to assume the mortgage responsibility as well. How do we go about this? Also be advised that we attempted to refinance and because of the state of the market our house is undervalued . What can we do ?

You may be able to get the mortgage lender to assign the mortgage to you but that won't change the rate. The only way you will get the rate changed is by refinancing.

Very little, you are wanting to get a lower interest rate, you can only do that though a refi.

Also some mortages can be assumed and others can not, you will have to call the lender and see if it is possible