A non-conforming mortgage is a home loan that does not meet the guidelines of government-sponsored enterprises (GSE) such as Fannie Mae and Freddie Mac. These loans often have higher interest rates and may be classified as jumbo mortgages if they exceed the conforming loan limit. Non-conforming mortgages can be based on factors such as loan-to-value ratio, debt-to-income ratio, credit score, and property type. These loans are harder for banks to sell, so they typically command higher interest rates.