These loans have a fixed principal and interest (P&I) payment for the life of the note. Escrows (taxes and insurance) are the only part of the entire payment subject to change.
10yr fixed, there are 120 payments at a fixed P&I rate which is the same rate as the 15yr fixed.
15yr fixed, there are 180 payments at a fixed P&I rate.
20yr fixed, there are 240 payments at fixed P&I rate which is the same rate as the 30yr fixed.
30yr fixed, there are 360 payments at a fixed P&I rate.
40yr fixed, there are 480 payments at a fixed P&I rate which is the same rate as the 30yr fixed.
Note: The shorter the maturity the greater the monthly payment. If you desire a fixed rate, these are the product choices. You can select the term that best suits ones requirements.