There are 2 cases in a city where we have branches. Are we allowed to close the lobby and keep only the drive-in open during this threat or would we need special approval from our regulator to do so?

As this is kind of a new phenomena, I would ask the regulators this question, unless your state has already mandated a shut down.

Stay safe!

If you can do at the drive up what you do in the lobby, I don't know why you'd have issues. It is temporary at best, but does your regulator look at motor banks differently than a lobby? That would be a strong indication to guide you.

Some would say though that doing this would be overkill. (No pun intended.) Other merchants are open for business. You might encourage more folks to use the drive up, and provide sanitizer inside. I wouldn't want to add to the alarmist perspective.