(a) Mortgages with adjustable rates or finance charges and home equity lines of credit. A creditor that makes an alternative mortgage transaction with an adjustable rate or finance charge may only increase the interest rate or finance charge as follows:

(1) If the transaction is subject to 12 CFR 226.5b, the creditor must comply with 12 CFR 226.5b(f)(1).

(2) For all other transactions, the creditor must use either:

(i) An index to which changes in the interest rate are tied that is readily available to and verifiable by the borrower and beyond the control of the creditor; or

(ii) A formula or schedule identifying the amount that the interest rate or finance charge may increase and the times at which, or circumstances under which, a change may be made.

(b) Renegotiable rates for renewable balloon-payment mortgages. A creditor that makes an alternative mortgage transaction with payments based on an amortization period and a large final payment due after a shorter term may negotiate an increase or decrease in the interest rate when the transaction is renewed only if the creditor makes a written commitment to renew the transaction at specified intervals throughout the amortization period. However, the creditor is not required to renew the transaction if:

(1) Any action or inaction by the consumer materially and adversely affects the creditor's security for the transaction or any right of the creditor in such security;

(2) There is a material failure by the consumer to meet the repayment terms of the transaction;

(3) There is fraud or a willful or knowing material misrepresentation by the consumer in connection with the transaction; or

(4) Federal law dealing with credit extended by a depository institution to its executive officers specifically requires that as a condition of the extension the credit shall become due and payable on demand, provided that the creditor includes such a provision in the initial agreement.

(c) Requirements for high-cost and higher-priced mortgage loans. (1) If an alternative mortgage transaction is subject to 12 CFR 226.32, the creditor must comply with 12 CFR 226.32 and 12 CFR 226.34.

(2) If an alternative mortgage transaction is subject to 12 CFR 226.35, the creditor must comply with 12 CFR 226.35.

(d) Other applicable law. Notwithstanding paragraphs (a) through (c) of this section, a housing creditor that is not making an alternative mortgage transaction pursuant to § 1004.3 of this part may make that transaction consistent with applicable State or Federal law other than this section.

(e) Reductions in interest rate or finance charge. Nothing in this section prohibits a creditor from decreasing the interest rate or finance charge on an alternative mortgage transaction.