Do cluster mailboxes in HOA common areas have to have ramps, concrete pad and handicapped parking space to be ADA compliant?

It depends.Yes. All mailboxes have to be accessible and if that requires ramps, clear floor/ground space, and parking then they must be provided to make the mailboxes accessible.If the oldest mailbox was built prior to the effective date of the FHA, 5/13/91, then it would not be required to comply with the FHA.