For an open-end, dwelling secured loan, are we required (per Reg Z) to state in the Note where the variable rate index is published? For example, we use the WSJ Prime and have always listed where it's published, but our new document vendor does not include this information.

Open-end - dwelling secured - you mean a HELOC?

Paragraph 40(f)(1)
1. External index. A creditor may change the annual percentage rate for a plan only if the change is based on an index outside the creditor's control. Thus, a creditor may not make rate changes based on its own prime rate or cost of funds and may not reserve a contractual right to change rates at its discretion. A creditor is permitted, however, to use a published prime rate, such as that in the Wall Street Journal, even if the bank's own prime rate is one of several rates used to establish the published rate.

2. Publicly available. The index must be available to the public. A publicly available index need not be published in a newspaper, but it must be one the consumer can independently obtain (by telephone, for example) and use to verify rates imposed under the plan.

However, in the account agreement/disclosure at account opening, you have this:

Official Interpretation
Paragraph 6(a)(1)(ii)

15. Variable-rate plan—index. The index to be used must be clearly identified; the creditor need not give, however, an explanation of how the index is determined or provide instructions for obtaining it.

Perfect. Yes, I'm referring to a HELOC.

Thanks again rlcarey!

Based on the Official Interpretation cited above, providing instructions for obtaining the index are only required in the disclosure at account opening? We currently have WSJ Prime and where it's published listed in both the disclosure AND account agreement (note).

Actually, it is required in the early HELOC disclosure under 1026.40 - See Models G-14A, G-14B and 15. 1026.6(a) does not specifically require it in the account opening disclosures - strange as that seems. However, it is commonly included.