Originally Posted by
sigep_nm
Youl only need to have a second class medical to operate with the privilages of a commercial pilot. Flight instruction is exempt from this status as you are operating as a flight instructor, not a commercial pilot.
That is correct. To be a flight instructor you only need a 3rd class medical. There are even times when you don't even need a medical at all to flight instruct; as long as the student is properly rated in the aircraft and is able to act as PIC.