In the United States, a conforming loan is a mortgage loan that both meets the underwriting guidelines of Fannie Mae and Freddie Mac (the Enterprises or GSE) and that does not exceed the conforming loan limit. The most well-known guideline is the size of the loan which, for 2022, was generally limited to $647,200 for one-unit single family homes in the continental US. Other guidelines include borrower’s loan-to-value ratio (i.e. the size of down payment), debt-to-income ratio, credit score and history, documentation requirements, etc.
In general, any loan that does not meet guidelines is a non-conforming loan. A loan that does not meet guidelines specifically because the loan origination amount exceeds the guideline limits during its acquisition year is known as a jumbo loan.