The Consumer Handbook on Adjustable-Rate Mortgages booklet states that to calculate the change in payment for an ARM, the lender must know the:

While the floor and ceiling are important in the context of ARMs, they do not directly determine the change in payment. The floor is the lowest interest rate the loan can reach, and the ceiling is the highest; however, without the index and margin, the specific payment change cannot be calculated.

The current principal balance and the annual percentage rate (APR) provide information about the loan's existing terms. However, they do not account for the adjustments that occur at the reset dates of an ARM, which rely on the index and margin to determine new interest rates and payments.

These dates are relevant for understanding the timeline of the mortgage, but they do not provide the necessary information to calculate changes in payment amounts. The payment adjustments depend on the index and margin rather than the specific dates of the loan's origination or the initial payment.