A conventional home loan is not guaranteed by a government organization, such as the Federal Housing Administration or the Department of Veterans Affairs. The qualifying criteria for a government-backed loan and a conventional loan aren’t much different, but conventional loans are likely to be harder to get and more stringent on qualifications. These loans adhere to Fannie Mae or Freddie Mac guidelines. About 35-50% of mortgages, depending on market conditions and consumer trends, are conventional mortgages. In other words, Fannie Mae and Freddie Mac guarantee or purchase 35-50% of all mortgages.