I just have a question as to when do I need to renew my 1st class medical after turning 40. Is it 6 months from the date of issue or 6 months from turning 40? I got my last medical in August but didn’t turn 40 until November. Just curious as to which date I should go by.

I had this discussion with a fed once. How old you were on the date of you physical determines it's duration.