A conventional mortgage is a loan that is not insured or guaranteed by the government. It is available through private lenders, such as banks and credit unions. Conventional mortgages are the most common type of mortgage in the United States. There are two types of conventional mortgages: conforming and nonconforming. Conforming loans meet the loan limits set by Fannie Mae and Freddie Mac, two government-sponsored enterprises that purchase mortgages from lenders and sell them to investors. Nonconforming loans do not meet these loan limits.