Can we monitor MMDA's for excessive transactions on a monthly basis even if their statement cycle is a different time frame such as every third Wednesday of the month? Or do we have to monitor on the statement cycle?

§204.2(d)(2) of Regulation D provides your answer. The operative part of the definition reads ". . .under the terms of the deposit contract or by practice of the depository institution, the depositor is permitted or authorized to make no more than six transfers and withdrawals, or a combination of such transfers and withdrawals, per calendar month or statement cycle (or similar period) of at least four weeks. . . ."

Making the transition to calendar month monitoring should be done delicately. After all, you don't want to alienate a valued customer just because a check or transfer that would have been counted in a different period falls into the transition month's count. I'd suggest that, if you have a customer whose transaction pattern gets picked up in the transition, you carefully review it and give the customer the benefit of the doubt. Perhaps you need to adjust the language of your initial contact letter or script when you advise customers of their first transgression so that you can tell them you're changing your counting method.

In our experience, customers who attempt to manage their transfers using calendar months vs. statement months are more successful. But regardless of the method, you'll always have cases of checks that are late-presented and "clump," especially around year-end.