Adjustment Periods:

The initial rate and subsequent changes can shift every month, every 3 months, 6 months, 12 months, 3 years, or other combinations. In order to compare loans, find out how long the teaser rate is in effect and how often the rate changes after the teaser period.

Just like with any other loan, the higher the rate on a specific program, the lower the fees ( actually, the fees are the same, but the lender is paying for them in exchange for the higher interest rate). In order to compare loans, you will have to choose a likely holding period for your property and evaluate the options based on that time frame.