A loan is called “Jumbo” when the amount of the mortgage exceeds the loan-servicing limits set by Fannie Mae and Freddie Mac — set at $484,350 for a single-family home in 2019 in all states (except Hawaii, Alaska, Guam, USVI and a few federally designated high-cost markets, where the limit is $726,525).
Jumbo mortgages can be used to purchase a primary residence, second home, or vacation home, including investment properties. Just like convention mortgages, they are available in a variety of terms, including fixed- and adjustable-rate loans. Because of the loan’s limited ability to be sold by the bank, these mortgages may require an increased down payment, come with a higher interest rate, and have stricter underwriting rules when compared to a standard loan, but each market and lender can vary widely and some jumbo lenders can offer more flexibility than with conventional loans.
The Fannie Mae website has more information on Single-Family Loan Limits: https://www.fanniemae.com/singlefamily/loan-limits#