Seriously, URM status is meant for people who either have been discriminated against because of their race or for people who lived in the manner of a certain culture and therefore have some disadvantages compared to others.
I'm 1/16th Cherokee, but no one would ever know I am nor have I ever lived on a reservation. Therefore, I am not URM.
And if you want to look at it from the perspective of AA being for the patients not the doctors, then an American Indian isn't going to feel anymore comfortable being with me (1/16) than they will be with a completely white doctor.
I agree with the poster above me, if the OP is what the username suggests you need to pull any apps that are considering you as URM BEFORE they meet you in an interview.