How Many Letters Do You Need?
AMCAS accepts up to 10 letters of evaluation. Each medical school sets its own minimums and maximums — most require 3–5 letters. The number is less important than the mix and quality.
Submitting more letters does not necessarily strengthen your application. Adcoms read the letters they need; redundant or weak letters waste their attention.
The Standard Required Mix
The expected mix for most MD applicants:
- 2 science faculty letters from professors who taught you in upper-division biology, chemistry, physics, or math courses.
- 1 non-science faculty letter from a professor in humanities, social sciences, or another discipline.
- 1 clinical letter from a physician (MD/DO) or PA you shadowed or worked with substantively.
- Optional: 1 research letter from a PI if you have significant research experience.
If your undergrad has a pre-health committee, they typically assemble a committee letter that combines these into one packet. Most medical schools accept (or require) the committee letter in place of individual ones.
Who Writes the Strongest Letters
Adcoms value specificity over title. A detailed letter from a professor who knew you through three semesters of coursework and one research project beats a generic letter from a Nobel laureate who barely remembers your name.
Signals of a strong writer:
- They have known you for at least one full academic year.
- They have seen you in more than one context (classroom + research, or two different courses).
- They can describe specific moments of your growth, not just your final grade.
- They have written letters for medical school applicants before.
Who NOT to Ask
Common mistakes:
- Family friends who are physicians but did not work with you. The letter will read as a personal favor, which is worse than no letter.
- Professors who taught you in only one large lecture course. They will struggle to say anything specific.
- TAs or graduate students. They can co-sign with the professor of record but standalone letters carry less weight.
- Coaches or employers from non-clinical jobs. Only useful as supplemental letters, not core required letters.
If you have a hesitant or weak option in mind, do not include them — submitting fewer letters is better than submitting a lukewarm letter that contradicts the rest of your application.
