No, that was tacitly required by FDIC examination procedures, but they were supersceded in 2005. Per guidance issued at that time, your bank should perform a risk rating for every MSB and assign them a level of risk based on that evaluation. The risk level you assign should drive the level of monitoring you impose and the documentation you require.
However, review your bank's policies and procedures for such requirements. It they are there, that is the equivalent of law or regulation within the 4 walls of your bank. Then, the answer would be "Yes," you must do it.
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In this world you must be oh so smart or oh so pleasant. Well, for years I was smart. I recommend pleasant.