Full disclosure, applied in 2021, interviewed and was rejected. According to feedback I got from them, the decision was largely because of my lack of clinical experience at that point. So take my advice with a grain of salt.
The whole point of the program is to give you extra time to pursue interests outside of medicine so that, when you eventually matriculate to medical school, you bring a diversity of lived experiences and perspective to contribute to their medical school class.
I've often found a question of what is a typical flex factor to be misguided. Unlike the rest of what goes into a good application for medical school that is usually common among applicants, like good clinical experience and service and grades, the flex factor should be highly individualized and unique to you. Whenever I work with students who are applying for this program, I encourage them to consider why they are applying in the first place. To be blunt, I know a lot of people apply to this program because it's a way to get a guaranteed admission to a T20 as a sophomore and not have to take the MCAT. I totally understand it, but if that is your only motivation for applying to this program I would recommend you at least reconsider once. Their admissions committee is really good at screening out people who are applying for those reasons instead of having a genuine flex plan.
Now, if that doesn't apply to you then why are you applying to this program? What do you hope to get out of it? What potential things can you accomplish by having 2 years in college to do stuff that a traditional pre-man student has little chance of being able to do? What things interest you about medicine and what unique aspects of your background and your passions, do you want to combine with your desire to become a doctor? Some of the flex factors that I have heard people do is add a major in theater and perform on Broadway, which they said would allow them to have a better understanding of human expression and better connect them with patients. Stuff like health technology, entrepreneurship, and global health are really common. That's not necessarily a bad thing, but it's very saturated.
My flex factor was that I wanted to do national security internships with the FBI and CIA and learn how to bring surveillance techniques and informatics structures from counterterrorism and national security over to how we practice public health. My idea was that our pandemic monitoring and medical data sharing is pretty archaic in the United States, but our national security is the best in the world in terms of the technology we use, so why not try to adapt tactics from the latter to the former.
Also, keep in mind that the committee will review how your flex factor relates to your current activities. If you say you're interested in doing health technology work, but you have no background or previous experiences in tech type stuff, they're going to know you're making up fluff. My flex factor worked because I had a lot of previous research/experience in infectious diseases and public health. So, if you're having trouble coming up with a flex factor, you can also look at what prior activities and experiences you have and see if there is a common theme there that extends beyond medicine.
Also, keep in mind that Mount Sinai is giving you a significant amount of flexibility with this program. I would lean away from flex factors that are along the lines of wanting to do more clinical research or get more involved in community service. These are activities that traditional premeds do a lot, and many students can take Gap years to pursue this more. From the perspective of the admissions committee, why would they accept someone 2 years earlier who plans on doing the kind of stuff that they have several regular MD applicants already applying with? A little cynical of a take, but just my opinion.
That's a lot, but hope that was at least somewhat helpful. Good luck!
