How Many Letters of Recommendation for Residency?

Dear Applicant,

The question has two answers and people keep merging them into one. How many letters you can have is not the same as how many letters a program gets, and only one of those numbers is fixed.

The number that is actually fixed

The AAMC's ERAS documentation is unambiguous about the cap: "Applicants may designate the assignment of up to four LoRs to each program."

Four. Per program. That is the whole rule.

What the same chapter does not do is cap the number of letters you can have uploaded overall. It governs how many you assign to any one program, not how large your library is. So the real structure of the decision is this: you collect some number of letters, and then, program by program, you choose up to four of them.

That distinction is the entire reason the four exists. It is not a limit designed to make you scramble for a fourth letter. It is a limit that assumes you might have five or six and want to send different ones to different places.

Nobody uploads a letter but your letter writer

You cannot upload your own letters. The chapter is explicit: "LoRs must be uploaded through the ERAS Letter of Recommendation Portal by the LoR Author or their designee."

You create the letter request, the system generates a Letter Request ID, and your writer or their designee uploads through the portal. That means part of your timeline sits with someone else, the same way a transcript does. If a letter is not in the portal, no amount of preparation on your end moves it.

The practical consequence is a scheduling one. September 2 at 9 a.m. ET is when applicants may begin submitting to programs, and September 23 at 9 a.m. ET is when programs may begin reviewing. Those dates come from the AAMC's 2027 ERAS timeline. A letter that arrives between them is a letter that arrived in time. A letter that arrives in October arrives after your file has already been read once.

The sentence that should change how you plan

Here is the one that costs people something real: "LoRs assignments to programs that have been applied to cannot be changed."

Read that again with your own list in mind. The letter is not what gets locked. The assignment does. Once you have applied to a program with a given set of letters attached, that pairing is final for that program. A better letter arriving in October cannot replace a weaker one you already sent somewhere in September.

This turns a question people treat as administrative into a sequencing decision. If you have three letters now and a fourth coming from someone whose letter you actually want, applying to your top programs today spends those three on exactly the programs where the fourth would have mattered most. That is not a reason to delay everything. It is a reason to know that "I will just swap it later" is not available to you.

It also means the ordinary advice to submit on day one is not free. Submitting early is usually right, and September 2 arrives with real pressure behind it. But if the difference between September 2 and September 8 is a letter you actually want in the file, the calendar is not the thing you should be optimizing.

Waiving your right to see them

The other irreversible choice on this screen is the waiver. Per the AAMC: "Applicants who waive their right to view a LoR are not permitted to view or obtain the LoR under any circumstances."

Under any circumstances is doing real work in that sentence. Not later, not on request, not if the writer offers. Most applicants waive, and there are reasonable arguments for why a waived letter reads as more candid. But it is worth making that choice deliberately rather than clicking through it, because it is the one decision on the page that you can never revisit.

So how many should you get

That is a question about your specialty and your file, and it is the kind of question your dean's office and your mentors are actually equipped to answer, because they know both. This brief does not do personalized advising and will not pretend to.

What the published rules will tell you is the shape of the answer. Four is the most any single program will see. Nothing stops you from having more than four in your library. Which four go where is a real choice, and it is a choice you make once per program.

What to do this week

Find out where each of your letters actually is, not where you assume it is. A letter your writer promised in July and a letter sitting in the portal are different objects, and only one of them can be assigned.

Then, before you apply anywhere, decide which four go to your top programs. Not because a rule requires it, but because the rule that does exist makes that pairing permanent.