The loan product commonly called 'Interest Only Mortgage' is an interest-only payment option which is offered on fixed rate (FRM) or adjustable rate (ARM) mortgages or on option ARMs. The option to pay ‘interest-only’ lets you pays only the interest portion of your monthly payment for a fixed period (three, five, seven or ten years). At the end of that period your loan becomes fully amortized, thus resulting in greatly increased monthly payments. Your new payment will be larger than it would have been if it had been fully amortizing from the beginning. The longer the interest only period, the larger the new payment will be when the interest only period ends.

Interest only payment plans are for borrowers who expect to earn a lot more in a few years and want to maximize their buying power now or who will invest the difference between an interest only and an amortizing mortgage payments, and who are confident that these investments will make money.

Payments made during the initial interest only period are based on the interest rate and loan balance and are applied towards interest only (they will not reduce the principle balance of your loan). Please note that the initial interest rate for the loan is established by your lender based on market conditions and may be lower than, or higher than the rate that is based on the index used to make rate adjustments.

After the initial interest only period the loan converts to a traditional ARM, monthly payments are based on the interest rate, loan balance and remaining loan term and are applied towards principle and interest. The interest rate will be adjusted periodically based on the index rate plus a margin (your rate will be equal to the index rate plus the margin, rounded to the nearest one-eighth of one percentage point, unless your interest rate cap limits the amount of change in the interest rate).