Guide

How many letters of recommendation do IM residency programs require?

531 Internal Medicine programs publish a rule on how many letters of recommendation they want, and between them they carry 539 readings, seven more than the program count. That gap is not a mistake: a handful of programs phrase the rule two different ways on the same page, and we keep both readings rather than pick the one we like better. 428 of the 538 readings ask for three letters. 78 ask for two. 19 ask for four. 11 ask for a single letter.

The full distribution

Three letters is by far the most common number a program names, but it is not universal, and the tail matters if you are deciding which letter writers to line up first. Here is every program that publishes a specific count, from zero to four:

Letters required	Programs
0 letters	2
1 letter	11
2 letters	78
3 letters	429
4 letters	19

The two programs at zero do not mean no letter is read; they mean the program's own page states a minimum of zero, which we read as no floor rather than as a rule against submitting one. We publish the number as written, not the number we think the program probably meant.

A floor and a ceiling are two separate facts

A program that writes "minimum of three (3) letters" is naming a floor: submit fewer and your application may be read as incomplete. A program that writes "at least 3, no more than 4" is naming a floor and a ceiling in the same sentence, and we record both numbers rather than collapsing them into one. A phrasing like "two or more letters" is a floor with no ceiling stated at all, which is a different commitment than "at least 1, no more than 4", where the floor is as low as it gets and the ceiling is the same four ERAS itself allows per program. Reading these as interchangeable is where an applicant under-submits for one program and over-submits for another, when the program's own sentence already told them which was which.

How ERAS actually assigns letters

Letters of recommendation are not attached to your application as a single packet; ERAS lets you upload multiple letters to your account and then assign, per program, which of them that program receives, up to a maximum of four letters per program. A program's minimum is a floor on how many of your assigned letters it expects to see; ERAS's own ceiling of four is why no program's stated maximum in our data goes higher than that. If a program states no number at all, the ERAS ceiling is still the practical one: four is the most any program can be sent, stated rule or not.

Why the number changes your planning, not just your count

A letter takes weeks to arrange, not days: you need to ask, the writer needs to say yes, and then the writer needs time to actually draft something specific rather than generic. If you are applying to a mix of three-letter and four-letter programs, the honest plan is to line up four writers, not three, because a fourth letter you have in hand costs you nothing at a three-letter program and a missing fourth letter can cost you at a four-letter one. The reverse is not true: a program with a floor of two or three will not penalize a fourth letter you choose to send if ERAS lets you, but it will absolutely notice one letter short of its own stated minimum.

What we refuse

Not every sentence a program publishes about letters survives our reading guard as a requirement. A preference for a particular kind of writer, such as "a letter from a US-based attending is preferred," is a preference about who signs the letter, not a rule about how many letters to submit, and it does not end an application the way a missing letter can. We do not publish a count of programs that state this preference, because that number is not one we have verified against the same standard as the counts above: we would rather leave a gap than print a figure we cannot stand behind. What we do publish is only the numeric floor or ceiling a program states in its own words, quoted and dated like every other fact on this site.

Counted on 10 September 2026 from 654 programs read. See how we read programs for the method, and start your own list, free for the 2027 cycle.