Would someone mind confirming that we are required to maintain consumer adverse action notices/supporting documents for 25 months from the date of notification? (Business loans require less time.) I'm looking at 202.12 and this is how I am interpreting it.

You are correct, Adverse Action Notices (and all information used in the analysis of the application) must be retained for 25 months after teh applicant is notified 202.12(b)

Does this apply to HMDA reportable applications or should those be retained for a longer period?

I'm not aware of anything that requires you to keep HMDA reportable transactions longer, but I would tell you to make sure you definitely destroy your adverse actions as the reg states because the examiners are strict about not keeping these things around. They will check!