A jumbo mortgage is a loan that exceeds the conforming loan limits. If the loan value (sales price minus down payment) is more than $417,000 then this is a non-conforming Jumbo mortgage loans. Jumbo mortgages are called non-conforming because they exceedx the conforming amount that can be backed by Fannie Mae or Freddie Mac, the federal government-sponsored entities that guarantee mortgages. Non-conforming loans that exceed conforming limits are not backed by the government entities Fannie Mae and Freddie Mac. Jumbo loans are backed by private investors and have slightly different guidelines. The conforming loan limit in Texas is any mortgage over $417,000, so home buyers in San Antonio seeking mortgage loans higher than this loan value can apply for a jumbo home loan; also called a non-conforming loan. Jumbo loans are typically used for large, single-family homes, and they have a different underwriting process and come with a slightly altered set of guidelines.