Where can I find the requirement on how long to retain documentation when we decide not to file a SAR?

I don't believe I've ever seen such a requirement for a non-filing. However, we keep ours at least from one BSA examination to the next, as they always ask for the documentation on the times that we chose not to file a SAR.

I keep mine 5 years.

Is that because of a regulatory requirement or just an 'abundance of caution (LOL)'? I didn't think that it would fall under the 5 year rule.

From one examination to the next should suffice; there is no record retention requirement.

Unless the regulators think that you have missed some SARs and order a look back. Having records of what was actually reviewed and what was not reviewed may help narrow the scope of such an enforcement order. But otherwise, I agree with the above comments.

I do agree with Randy that if the bank's process is called into question, evidence of what was reviewed and how decisions were reached can limit (or eliminate the need for) the scope of a lookback. A lookback can easily extend farther back than the prior examination.

Just such a look-back is involved in the $10 million CMP we reported in today's Top Stories. Here's a separate thread with some thoughts on that enforcement action.

Thank you all for your input.