Fixed rate mortgage the interest rate, and hence monthly payment, remains fixed for the life (or term) of the loan. In the US, the term is usually for 10, 15, 20, or 30 years. In the UK the fixed term can be as short as five years, after which the loan reverts to a variable rate.

Adjustable rate mortgage, the interest rate is fixed for a period of time, after which it will periodically annually or monthly adjust up or down to some market index. Adjustable rates transfer part of the interest rate risk from the lender to the borrower, and thus are widely used where unpredictable interest rates make fixed rate loans difficult to obtain. Since the risk is transferred, lenders will usually make the initial interest rate of the Adjustable rate mortgage's note anywhere from 0.5% to 2% lower than the average 30-year fixed rate.

In most scenarios, the savings from an Adjustable rate mortgage outweigh its risks, making them an attractive option for people who are planning to keep a mortgage for ten years or less.

A partial amortization or balloon loan is one where the amount of monthly payments due are calculated (amortized) over a certain term, but the outstanding principal balance is due at some point short of that term. A balloon loan can be either a Fixed or Adjustable in terms of the Interest Rate. Many Second Trust mortgages use this feature. The most common way of describing a balloon loan uses the terminology X due in Y, where X is the number of years over which the loan is amortized, and Y is the year in which the principal balance is due.