At application
For an adjustable-rate loan secured by a home, the creditor must give you the Consumer Handbook on Adjustable Rate Mortgages, or a suitable substitute, along with the loan program disclosures.
Within days of applying
The Loan Estimate has to be delivered or mailed no later than three business days after the lender receives your application. It shows how the rate and payment can change in later years.
Before the first adjustment
The creditor, assignee or servicer must send a notice as a separate document, at least 210 days and no more than 240 days before the first payment at the adjusted level is due. If that payment falls within the first 210 days after closing, the notice comes at closing.
Before later payment changes
When an adjustment changes the payment, a notice must arrive at least 60 days and no more than 120 days before the first payment at the new level. Loans that adjust very frequently follow shorter windows.
What to do with a notice
Put the new rate it states into the calculator as the index plus margin, and check the payment against the table. The notice is also the moment to look at the remaining caps.