This is a great question! It is definitely in your best interest to get letters from 2 science professors and 1 non science. If you feel like you didn't get to know the professors well in the classes since they were big could you reach out to them now and try to be a teaching assistant for them? Or try to work on some sort of project with them? I'm wondering if anyone else in this group has run into a similar hurdle? For me it was a little easier because I had engineering courses that were much smaller so my engineering professors knew me quite well and I used them as my science professors. "Strictly speaking, medical schools would like to see your science letters come from biology, chemistry, or physics (BCP) professors. While many schools will also accept a science letter from a math, computer science, engineering, or other science professor, other schools won’t. Therefore, you should check directly with your top-choice schools if you intend to submit a science letter from a non-BCP professor." So math might actually count! CNA course I'd say they probably count as either a non science or an extracurricular. I'd look at a couple med school websites that you have your sights set on and just read their blurb about what types of letters they want! Each school has slightly different asks so you will want to make sure you have 3-6 letters ready on hand to supply to meet each school's requirements. I'll attach the one for U of A Phoenix. Posting a good link to check out below! https://www.shemmassianconsulting.com/blog/medical-school-letter-of-recommendation