This is what is confusing me....it seems like four or so years ago they changed 61.23(d) to allow you to exercise first class privileges for 12 months for those under the age of 40. Does that extend the duration of the first class medical, or just extend the privileges? It seems that there are several interpretations here. I know at my current airline, if you are under 40, it's good for 12 months, end of story, regardless of type rides, ratings, etc.