Hi! I thought I would respond to some of your concerns...to enlighten you in the historical backgrounds of Underrepresented minorities IN MEDICINE....
AAMC identifies AA, NA, MEX, PR because through history, since medical school admissions, those were the most abudant, and in many cases, the only minority groups that coexisted with White Americans in the United States. Therefore, it makes sense that they only focus on the groups that throughout history, have suffered longer periods of discrimination and have been secluded from access to higher education. I agree with you, many Latino groups now day, remain underrepresented in higher education, particularly those from South and Central America. This explains the shift that Medical Schools have taken in broadening their definition of URMs.
Unfortunately, unless you check the Mex, or PR box, you will not be considered URM. You will be considered a Minority applicant, by the virtue of your Peruvian background. However, do expect that schools have always been and will continue trying to recruit more conciously URMs, than other minorities....
I hope that you used your life experiences in support of your interest to pursue a career in medicine. this will DEFINITELy bring a third dimension into the teaching and practice of medicine, wherever you choose to attend!