A balloon mortgage allows you to enjoy low monthly payments for several years — with a big catch. A balloon mortgage is a loan with low initial payments, but it requires the borrower to repay the balance in full in a lump sum.A balloon loan what it is it's essentially a term a certain duration of time and then it leads to a maturity date when the full loan amount is due. A balloon mortgage is just another lien and type of mortgage that once it matures to a specific time, the remaining balance is due all at once. Learn everything you need to know about balloon notes in mortgage loans. Find out how they work and how they can affect your finances.