Who should write your medical school letters? A medical student explains who to ask, science professor and physician requirements, PI letters, and what admissions committees likely want.
Choosing who should write your medical school letters of recommendation can feel strangely difficult because there is no single combination of writers that works for every applicant and every medical school. You may have a science professor who taught you but barely knows you, a research mentor who has worked beside you for two years, a physician who has watched you interact with patients, and an employer who probably knows your character better than all three. Then you start reading medical school websites and realize that one program specifically asks for science faculty while another seems perfectly happy to receive letters from almost anyone who knows you well.
The best place to start is with a simple rule: first satisfy the letter requirements of the medical schools on your list, and then choose the people within those requirements who know you best and can write about you with specific examples. A prestigious title does not make up for a weak relationship. A famous physician who met you four times is usually much less useful than a professor, research mentor, supervisor, or physician who has spent enough time with you to describe how you think, work, communicate, respond to feedback, and treat other people.
When I was building my own recommendation letters, I received letters from professors, research mentors, and physicians. What made those relationships useful was not simply what each person had after their name. They had actually spent enough time around me to see how I worked over months or years, which gave them something meaningful to write about beyond my grades and résumé. I go much deeper into how I built those relationships in my How to Get a Good Letter of Recommendation guide.
Your goal is therefore not to assemble the most impressive collection of job titles. You want a group of letter writers who satisfy your schools’ rules and collectively provide firsthand evidence that you have the academic ability, character, maturity, communication skills, reliability, service orientation, scientific curiosity, and other qualities medical schools are trying to evaluate.
Who Should Write Your Medical School Letters of Recommendation?
For a traditional applicant, your potential medical school letter writers will often include science professors, non-science professors, research mentors or principal investigators, physicians or clinical supervisors, employers, volunteer supervisors, and other mentors who have observed you closely. You absolutely do not need a letter from every category, and some schools restrict how many letters you can submit, so adding more people is not automatically better.
A common starting combination for traditional applicants is two science faculty letters, another academic letter, and one or two letters from meaningful research, clinical, employment, or service experiences. I would treat that as a planning framework rather than a universal medical school requirement, because current policies vary considerably from school to school.
When I checked medical school admissions pages for this article in September 2026, Johns Hopkins stated that applicants without a committee or advisor letter should provide two letters from science faculty who taught them and one from a non-science faculty member who taught them. Stanford, in contrast, stated that it does not have specific requirements for who writes its recommendation letters and encourages letters that illuminate qualities such as leadership, originality, research, clinical exposure, cultural humility, and advocacy. Michigan similarly allows recommenders to be any individuals capable of objectively assessing important personal qualities.
That is why I would never finalize your writers based solely on somebody online saying, “Everyone needs two science letters and one non-science letter.” Build your preliminary list that way if it gives you good coverage, but then compare it against the actual requirements of every school you plan to apply to.
If you are still putting the rest of your application together, my month-by-month medical school application timeline walks through when I would identify and ask letter writers alongside the MCAT, personal statement, AMCAS, secondaries, and the rest of the application process.
What Makes Someone a Good Medical School Letter Writer?
I would evaluate a potential writer on five things: whether the person satisfies a school requirement, how directly they have observed you, how long and meaningfully they have known you, whether they can provide specific examples, and whether their letter adds something useful that your other letters do not already show.
This lines up extremely well with the AAMC’s own Guidelines for Writing a Letter of Evaluation for a Medical School Applicant. The AAMC asks letter writers to explain how long and in what capacity they have known an applicant, distinguish between direct and indirect observations, describe actual behaviors they witnessed, and provide contextualized comparisons when appropriate. The guidelines also emphasize that the quality of the information matters more than the length of the letter.
Think about what that means when you are choosing between two professors. Professor A may be the chair of the biology department, but perhaps you sat in the back of a 300-person lecture and never spoke to them. Professor B may be an assistant professor whose smaller course you took for a semester, whose office hours you attended, and who watched you improve after struggling with an early exam. Professor B has much more raw material for an actual evaluation.
I like thinking about every prospective recommender by asking, “What can this person credibly prove about me that an admissions committee cannot already learn from my transcript and AMCAS activities?” If your only answer is that the professor can confirm you earned an A, that letter may satisfy a requirement, but it may not be your strongest option if another eligible professor can explain how you learned, participated, helped classmates, responded to setbacks, or approached difficult material.
Do Medical School Letters Have to Come From Professors?
Not all medical school letters need to come from professors, but some schools specifically require faculty letters. This is one of the most important reasons to check each medical school’s current admissions website rather than assuming that a research mentor, physician, employer, or volunteer supervisor can substitute for a required professor.
There are also schools that take a much broader approach. The University of Florida, for example, says it does not specify who must provide its recommendation letters and instead wants direct observations that corroborate qualities such as integrity, persistence, communication, adaptability, leadership, collaboration, and intellectual rigor. UCSF says letters from upper-division instructors who know an applicant well are particularly informative while also noting that letters documenting contributions to research or health-related work are of interest to the admissions committee.
This is why “Who knows me best?” is only half of the decision. The other half is “Who is this school willing to count?” You need both answers before replacing a professor with somebody who may personally know you better.
How Many Science Professors Should Write Your Medical School Letters?
Two science-professor letters remain a very useful number to plan around because a number of medical schools either require or traditionally expect multiple academic science evaluations. However, there is no AMCAS-wide rule stating that every applicant must have exactly two science professors, and individual schools can set different standards.
If you have two science faculty members who know you well, I would generally try to secure both early because doing so keeps more schools available to you. It is much easier to decide later that a school only needs one of those letters than to discover in June that one of your target schools requires two science faculty letters and you never asked a second professor.
Your school list ultimately controls the answer. Check requirements while you are still selecting recommenders rather than after letters have already been collected, because changing your entire letter strategy late in the application cycle creates stress that is completely avoidable.
What Counts as a Science Professor for Medical School Letters?
There is no single definition you should assume every medical school uses. Some schools describe acceptable writers by department, some specify subjects such as biology, chemistry, biochemistry, or physics, and others simply request academic faculty or people capable of assessing your scientific preparation.
This creates an especially important distinction between taking a class from a professor and conducting research with a scientist. Your research PI may be a biology professor and may know you extremely well, but that does not automatically mean their research letter satisfies a school’s requirement for a “science professor who taught you.” If the language specifically refers to faculty who taught you in coursework, I would not assume a laboratory relationship counts unless the school says that it does.
The same caution applies to borderline disciplines and unusual courses. Rather than trying to reverse-engineer what an admissions office “probably” considers science, read its current wording and contact the program when your situation genuinely falls into a gray area.
Can a Non-Science Professor Write a Medical School Letter?
Yes, and a strong non-science professor can give an admissions committee information that your science letters may not provide. A humanities or social-science professor who knows you well may be able to discuss your writing, communication, ethical reasoning, curiosity, classroom participation, ability to understand different perspectives, or the way you contribute to discussion.
This can make the collection of letters stronger because your recommenders do not all need to tell the same story. If two science professors already establish that you can handle difficult scientific material, a professor who watched you lead thoughtful discussions or develop into a much stronger writer may broaden the committee’s view of you.
Some medical schools specifically ask for a non-science faculty letter while others do not. I would therefore secure one when it fits both your relationships and school requirements rather than treating a non-science professor as either universally mandatory or universally unnecessary.
Can Your Research PI Write a Medical School Letter?
A research PI can be one of your strongest medical school letter writers when research has been an important and sustained part of your application. A PI may have watched you learn experimental techniques, troubleshoot failed experiments, work independently, collaborate with a research team, present results, write abstracts or manuscripts, and gradually take on more responsibility.
Those observations can make the letter particularly valuable because “research experience” on AMCAS tells an admissions committee what you did, while a detailed PI letter can explain how you actually functioned as a researcher. For applicants whose application emphasizes research heavily, leaving out a mentor who supervised hundreds or thousands of hours of that work can sometimes create an obvious gap in the story your letters tell.
However, I would not automatically use a PI letter as a replacement for a required science-professor letter. A scientist who supervised your research may satisfy one school’s policy and fail another school’s more specific classroom-faculty requirement. This is one of the most common areas where the title of the recommender can sound correct while the relationship itself does not match the school’s wording.
For MD-PhD applicants, research letters become even more important. Current UMass Chan guidance, for example, specifically calls for letters from at least two recent research supervisors for applicants to its Medical Scientist Training Program, which illustrates how differently research-intensive pathways can treat recommendation letters.
Can a Physician Write Your Medical School Letter of Recommendation?
Yes. A physician can write a medical school recommendation letter, and it can be excellent when the physician has actually supervised or worked closely with you over enough time to evaluate your behavior.
A physician who employed you as a medical assistant, supervised you in a clinical job, worked with you longitudinally in a free clinic, or mentored you through sustained patient-facing work may be able to discuss reliability, communication, maturity, empathy, teamwork, initiative, and how you interact with patients and staff. Those are meaningful observations because they come from actually watching you function in a clinical environment.
A physician’s degree by itself does not make the letter strong. If the relationship amounts to occasionally standing in the corner while the physician sees patients, there may not be enough direct observation to produce anything beyond broad praise.
Do You Need a Physician Letter for Medical School?
You do not need a physician letter simply because you are applying to medical school. Some programs may require or encourage a clinical or physician-related evaluation, while many others do not specifically require a physician at all.
I would therefore check your school list before spending months trying to manufacture a physician relationship solely because somebody online told you every medical school expects a doctor’s recommendation. If none of your schools requires one and your physician letter would be generic, I would much rather submit an allowed letter from someone who knows you exceptionally well.
If a physician already knows you closely through meaningful clinical work, the calculation changes. You are no longer choosing the person because “MD” or “DO” looks impressive after their name; you are choosing them because they have direct evidence of how you behave in an environment relevant to medicine.
Do You Need a DO Letter for Osteopathic Medical School?
There is not one universal rule requiring every osteopathic medical school applicant to submit a letter from a DO physician. AACOM specifically tells applicants that recommendation-letter requirements vary among individual osteopathic medical schools, and current schools demonstrate that variation in practice.
If you are applying to DO schools, look at each program’s current requirements and recommendations rather than relying on an old rule repeated online. When a school requires a physician letter, encourages a DO letter, or places particular value on demonstrating your understanding of osteopathic medicine, plan accordingly.
A genuine longitudinal relationship with a DO can certainly produce a strong letter. I just would not create an artificial shadowing experience and ask for a generic letter merely to place the letters “DO” inside your application if the schools you are applying to do not require it.
Can a Doctor You Shadowed Write Your Medical School Letter?
They can, but a shadowing letter is only as useful as the relationship behind it. Shadowing is inherently observational, which means the physician may have had far fewer opportunities to evaluate your performance than somebody who actually taught, employed, or supervised you.
This is one area where current admissions commentary is especially useful. LSU Health Shreveport tells applicants that letters from physicians and other people outside the applicant’s professors or committee often provide limited useful information, and its admissions FAQ specifically warns that physicians who know applicants only through typical shadowing may have little that distinguishes one student from another.
That does not mean every shadowing letter is bad. If you spent substantial time with the same physician, discussed cases and healthcare with them, participated appropriately in projects or other work, and developed an actual mentoring relationship, that person may know you quite well. I would judge the depth of the relationship, not the label “shadowing.”
Can a Teaching Assistant Write a Medical School Letter?
Sometimes, but this depends heavily on the medical school’s wording. If a school specifically requests a faculty member or professor who taught you, a graduate teaching assistant may not satisfy that requirement even if the TA interacted with you more than the professor did.
This situation is extremely common in large science courses because the TA may know your work, participation, and personality much better than the professor whose name appears on the syllabus. When possible, one option is to ask whether the professor can incorporate input from the TA into a faculty letter, but the exact arrangement should still comply with the school’s requirements.
Do not assume that every medical school handles TAs the same way. Some schools are more flexible about who can evaluate you, while others define acceptable academic recommenders narrowly enough that a TA would not count.
Can an Employer or Clinical Supervisor Write a Medical School Letter?
An employer or clinical supervisor can be an excellent additional writer, particularly if you worked closely with that person for a meaningful period of time. They may have watched you show up reliably, handle difficult situations, communicate with coworkers, accept feedback, solve problems, interact with patients, take initiative, and function when work became stressful.
For gap-year and nontraditional applicants, this type of evaluation can become even more valuable because your strongest recent relationships may exist in the workplace rather than a classroom. Current Michigan admissions guidance allows recommendations from any individuals capable of objectively assessing qualities such as integrity, dependability, teamwork, resilience, altruism, and desire to learn, demonstrating why a supervisor can sometimes provide exactly the kind of evidence a school wants.
An employer still does not automatically replace a professor when a school requires an academic letter. Use strong professional letters to broaden your file while making sure the required academic pieces are also covered.
Can a Volunteer Coordinator Write a Medical School Letter?
Yes, when the school allows additional letters and your volunteer supervisor knows you well enough to write something substantive. A long-term service mentor may be especially well positioned to discuss service orientation, reliability, teamwork, empathy, leadership, communication, and your ability to work with people whose experiences differ from your own.
The same rule applies here that applies everywhere else in this article: hours alone are not what make the recommender valuable. Someone who signed a volunteer-hours sheet but barely interacted with you probably cannot provide much insight, while a coordinator who supervised you for two years and watched you assume increasing responsibility may have a great deal to contribute.
If service is one of the defining parts of your application, a strong letter from that environment can also provide corroboration. Your personal statement and activities section tell admissions committees how you understood the experience; an independent supervisor can show what your involvement actually looked like from somebody else’s perspective.
Does the Prestige of Your Medical School Letter Writer Matter?
I would choose specificity over prestige almost every time once both writers satisfy the school’s requirements. An impressive title cannot create observations that never happened.
Imagine choosing between a nationally recognized physician who spoke with you occasionally during a summer experience and a less famous physician who supervised you every week for two years. The second physician may be able to describe the first time you struggled with a patient interaction, how you responded to coaching, how your responsibilities expanded, how the staff came to trust you, and what they observed about your growth. The famous physician may only be able to say you were bright, pleasant, and interested in medicine.
The AAMC’s guidance makes the reason fairly clear. Letter writers are specifically encouraged to explain the nature and duration of their relationship with the applicant and focus on behaviors they directly observed. A title does not substitute for any of that.
Should You Ask a Famous Doctor, Department Chair, or Medical School Faculty Member?
Only when that person genuinely knows you well enough to evaluate you. Do not choose somebody primarily because you hope an admissions committee will be impressed by the name at the bottom of the page.
Connections can sometimes tempt applicants into thinking that a senator, alumnus, famous physician, hospital executive, department chair, or faculty member at the medical school will carry special weight. An admissions committee is still going to ask what that person actually knows about you.
If the letter essentially says, “I know this applicant and think they would make a wonderful physician,” it provides very little evidence. If that same department chair has mentored your research for three years and can compare you with dozens of previous students, the title becomes secondary to the genuinely strong evaluation they can provide.
What Should Each Medical School Letter Writer Add to Your Application?
I would avoid choosing five writers who all prove exactly the same thing. Your letters work better as a collection when they give an admissions committee several independent windows into who you are.
A science professor might establish intellectual curiosity, scientific reasoning, academic resilience, and how you learn. A research PI might demonstrate independence, persistence, scientific inquiry, and how you respond when an experiment fails. A clinical supervisor might discuss your reliability, empathy, communication, and patient interactions. A service mentor might provide examples of commitment, humility, leadership, and how you work with a community over time.
This does not mean you need one writer for every competency or that you should orchestrate letters as though you are assigning people predetermined talking points. I would instead look at your group before submitting it and ask whether the writers are likely to provide genuinely different observations of you.
The AAMC’s current Premed Competencies include areas such as learning and growth, empathy, ethical responsibility, interpersonal skills, reliability, resilience, service orientation, teamwork, critical thinking, scientific inquiry, and communication. A strong collection of letters can reinforce several of those qualities from independent perspectives instead of simply repeating that you earned good grades.
How Do You Choose Between Two Possible Letter Writers?
When two people both satisfy the requirement, I would choose the person who has the stronger evidence, not necessarily the more prestigious position or the class in which you earned the slightly higher grade.
Ask yourself what each person has actually watched you do. How long have they known you? Have they seen you outside a single final grade? Did you attend office hours, work on a project, discuss material regularly, conduct research with them, or remain in contact after the course? Have they watched you receive feedback or work through difficulty? Could they tell a story about you without needing your résumé to remind them who you are?
I would also think about enthusiasm. There is a difference between someone who agrees to submit a letter and someone who seems genuinely excited to advocate for your readiness through a detailed evaluation. When I asked for recommendations, I wanted people who had enough experience with me that the request made sense based on the relationship we had already built.
This is why my How to Get a Good Letter of Recommendation guide focuses so much on what happens before you ever ask. Strong letters usually grow out of sustained relationships rather than a perfectly worded email sent two weeks before the deadline.
Should You Ask Someone Who Gave You an A but Barely Knows You?
Sometimes you may have to, especially when you need to satisfy an academic requirement and attended large lecture courses. However, an A alone does not guarantee that a professor can write a detailed recommendation.
Your transcript already shows the admissions committee your grade. A professor becomes more useful when they can add context that the transcript cannot provide, such as how you approached difficult material, participated, improved, contributed to the learning environment, sought feedback, demonstrated curiosity, or performed relative to other strong students.
If you are still several months or a year away from applying, this is one reason I recommend using office hours and developing real academic relationships before recommendation season arrives. You do not need to manufacture friendship with a professor, but giving someone opportunities to actually see how you think makes it much easier for them to evaluate you later.
Should You Ask a Professor if You Got a B in Their Class?
A B does not automatically make someone a bad recommender, particularly when the professor knows you exceptionally well and has meaningful context about your performance or growth. The grade is only one part of what they observed.
However, I would think carefully about what the professor is likely to say when comparing you with other students. If another eligible professor knows you equally well and saw you perform more strongly, that person may provide a cleaner academic evaluation.
The relationship can sometimes make a lower grade meaningful if the professor witnessed substantial improvement, persistence, curiosity, or unusual circumstances and can discuss those observations positively. I would not choose a lower-grade professor merely because you hope the letter will explain away a weak performance, though; the writer still needs to be genuinely enthusiastic about your candidacy.
Should You Get a Committee Letter or Individual Letters?
If your undergraduate institution offers a premedical committee letter, begin by learning its process and then checking how the medical schools on your list treat committee letters. AMCAS recognizes committee letters, letter packets, and individual letters as distinct letter types, while each medical school decides what it wants applicants to submit.
The AAMC explains that medical schools value committee letters because they can provide an integrated institutional perspective assembled from faculty observations and other information about the applicant. That can make the committee evaluation much more than simply several individual letters stapled together.
A committee letter may also satisfy requirements that would otherwise call for several individual academic letters at certain schools. That does not mean you should assume it does so everywhere or skip your institution’s instructions, so I would coordinate your committee process and individual writers early.
You can see where I place committee-letter planning within the rest of application season in my medical school application timeline and AMCAS checklist.
Who Should Write Medical School Letters for Nontraditional or Gap-Year Applicants?
If you have been out of college for several years, your strongest current recommenders may naturally come from employment, research, graduate education, clinical work, or service. A supervisor who has spent 40 hours per week around you for two years may know your current abilities far better than a professor whose class you took six years ago.
The difficulty is that being a nontraditional applicant does not automatically erase every academic-letter requirement. Some medical schools provide specific alternatives for applicants who have been away from school, while others continue to request faculty evaluations or define acceptable substitutions themselves.
Current UMass Chan guidance is a good example of why you need to read the details: applicants without a committee letter are given specific faculty expectations, while applicants who completed certain postbaccalaureate or biomedical graduate programs are expected to provide a program-director letter instead.
I would therefore start with the schools, identify which academic requirements truly apply to you, and then use your more recent supervisors to provide the strongest possible picture of who you are now.
Who Should Write Letters for MD-PhD Applicants?
For MD-PhD applicants, significant research mentors should usually be central to the letter strategy because programs are evaluating your potential not only as a medical student but also as a future physician-scientist. Someone who directly supervised your research can discuss independence, experimental reasoning, persistence, intellectual ownership, troubleshooting, collaboration, and how your scientific thinking developed.
The more substantial your research experience, the more noticeable it can become if nobody who supervised that work evaluates you. A research-heavy application that describes thousands of hours in a laboratory but contains no letter from a major research mentor may naturally leave reviewers wondering why.
You still need to satisfy the regular medical school requirements for the programs on your list. Research letters add a critical perspective, but they do not automatically replace every academic letter required for the MD portion of the admissions process.
Who Should NOT Write Your Medical School Letters?
I would generally avoid family members, close personal friends, people chosen almost entirely for prestige, supervisors who barely remember you, physicians you shadowed only briefly, and anyone you suspect will write a lukewarm or generic evaluation. The common problem across those categories is not simply who they are; it is that they may lack the professional distance or firsthand evidence required to provide a useful evaluation.
Current UCSF admissions guidance explicitly discourages character references from family, friends, or associates and emphasizes instructors who know applicants well, while UMass Chan similarly discourages letters from family and friends.
I would also hesitate before adding an extra letter just because AMCAS lets you create another entry. More letters create value only when they satisfy a requirement or add meaningful information. Three or four strong, complementary evaluations can be much better than a pile of repetitive letters saying that you are intelligent, pleasant, and hardworking.
What Medical School Admissions Leaders Say About Choosing Letter Writers
For this article, I specifically searched guidance from admissions deans, medical school admissions committees, and official admissions offices rather than relying only on third-party admissions websites. The pattern was remarkably consistent: admissions professionals want direct observation and specific evidence, and they repeatedly emphasize how well the writer knows the applicant.
Benjamin R. Chan, MD, an associate dean of admissions interviewed by the American Medical Association, advised applicants to build relationships with prospective recommenders by doing things such as attending office hours and actually allowing mentors to learn their story, goals, and personality. His point was practical: someone invested in you because they genuinely know you is in a much better position to write a meaningful recommendation. You can read the AMA’s admissions-dean discussion of medical school recommendation letters here.
The AAMC also has recommendation-letter advice written from an admissions-dean perspective, explaining that letters can provide context for qualities already visible elsewhere in the application or introduce new evidence, and that receiving perspectives from people who know an applicant in different settings helps create a more complete picture.
Individual admissions committees reinforce the same idea. Florida says it reads letters for direct observations demonstrating competencies such as persistence, integrity, intellectual rigor, communication, adaptability, and leadership. Michigan specifically tells applicants to choose writers who know them well. UCSF says upper-division instructors who know applicants well tend to provide particularly informative evaluations.
When you combine all of that guidance, I would not ask, “Who has the most impressive title?” I would ask, “Which eligible people have accumulated enough firsthand evidence to explain what I am actually like as a student, researcher, coworker, clinician-in-training, teammate, and person?”
What Reddit and r/premed Say About Medical School Letter Writers
I also searched Reddit, particularly r/premed, and summarized the recurring themes I found rather than treating any one anonymous comment as admissions policy. That distinction is important because Reddit is useful for discovering where applicants repeatedly become confused, but your medical schools and application services remain the authoritative sources for actual requirements.
One of the clearest patterns was confusion about physician letters. In a 2026 r/premed discussion asking whether a physician recommendation was necessary for MD applications, some commenters said they had applied successfully without one, while others remembered schools with specific clinical-letter requirements. Other users then checked individual policies and found that some supposed “physician requirements” were actually broader requirements allowing another healthcare professional or clinical supervisor.
That discussion captures exactly why I would not build your letters from Reddit consensus. Applicants may have completely different school lists, and a statement that was true for one person’s 20 schools may be wrong for your 25.
Another recurring r/premed theme was that relationship depth beats title when the school’s requirements allow both writers. Applicants repeatedly wrestle with choices between a high-ranking professor or physician who barely knows them and someone less prestigious who has actually worked with them closely. That informal advice lines up unusually well with the AAMC’s official emphasis on direct observations, duration of the relationship, and specific behavior.
The useful takeaway from Reddit is therefore not a universal letter formula. It is the number of applicants who discover a school-specific requirement late, realize that a physician they planned to use barely knows them, or have to choose among more recommenders than a school accepts. You can avoid most of those problems by mapping requirements before you ask for your final set of letters.
What Student Doctor Network Says About Who Should Write Your Letters
I separately searched Student Doctor Network and reviewed its dedicated letters-of-evaluation discussions, including the official 2025–2026 thread. Again, I am summarizing the recurring advice rather than treating forum posts as replacements for a medical school’s published requirements.
The SDN letter FAQ uses the familiar two-science-plus-one-non-science combination as a common starting point, but it immediately warns applicants that every school is different and tells them to verify individual medical school requirements. It also identifies research PIs, employers, physicians, and volunteer supervisors as potentially helpful additional writers when those individuals know the applicant’s work well.
One of the most useful points in that SDN discussion is that a detailed evaluation from someone who knows you can be more valuable than a tepid letter from a famous person. The thread also contains real applicants discovering after the fact that certain schools had requirements they had not planned for, particularly non-science or other specific writer categories.
There was also a recent example of an applicant debating whether to use a physician shadowing letter, with a verified SDN staff member noting that many shadowing letters end up as generalized praise because the physician did not have enough opportunity to evaluate the student. That does not prove every shadowing letter is weak, but it reinforces the same principle we see in official admissions guidance: observation creates substance.
What I like about comparing SDN, r/premed, AAMC guidance, and actual medical school admissions pages is that the overlap becomes obvious. The internet forums are full of debates about titles and categories, while the official guidance keeps returning to what the person actually observed and whether the letter meets the school’s rules.
How I Would Build a Medical School Letter Portfolio
For a fairly traditional applicant with several good relationships, I would begin by securing enough academic writers to cover the most restrictive schools I am seriously considering. If that means two science professors and a non-science professor for my school list, I would rather have those relationships established early than scramble for them once applications are open.
Then I would look at the major experiences that define the rest of my application. If research is central to my story and my PI knows me extremely well, that person would be high on my list. If I spent two years working directly with a physician who watched me interact with patients and become increasingly responsible, that could be another powerful evaluation. If my strongest longitudinal experience was instead community service or employment, I would consider the supervisor from that setting.
I would then compare the entire group and remove unnecessary duplication. If three people are likely to say almost exactly the same thing about me, I would ask whether another eligible recommender can provide a perspective the committee would otherwise never see.
Finally, I would create a school-by-school letter map before assigning anything. My 2027 AMCAS Application Checklist and Medical School Cost Calculator is useful for this because I built the application tracker to separate letter planning, receipt, assignment, and overall application completion rather than treating “I asked my professor” as though the entire letter requirement is finished.
Can You Send Different Recommendation Letters to Different Medical Schools?
Yes. AMCAS allows you to create letter entries and designate which letters are sent to particular participating schools, subject to the application service’s rules and each school’s own requirements. You therefore do not necessarily have to send exactly the same set of individual letters everywhere.
This becomes useful when one school specifically wants a certain faculty letter while another allows a clinical or research letter that you consider stronger. It is also why having several good letters available can provide flexibility without forcing every school to receive every recommendation you collected.
Do not interpret that flexibility as permission to ignore a school’s maximum. Some programs explicitly cap the number of letters they want to review, and sending extra material after a school tells you not to can make your application look less carefully prepared.
The current 2027 AMCAS Applicant Guide should be your primary reference for the mechanics of creating and assigning letter entries. I also explain how letters fit into submission and verification in my AMCAS application timeline guide.
Can You Submit AMCAS Before Your Recommendation Letters Are Ready?
Yes. Your recommendation letters do not need to be received before you submit your AMCAS primary application or before AMCAS begins the normal verification process.
This is worth understanding because applicants sometimes delay an otherwise finished primary while waiting for one professor to upload a letter. The medical school may eventually require that recommendation before considering your file complete, but AMCAS submission, AMCAS verification, letter receipt, and school-level completion are separate milestones.
I cover this timeline in much more detail in my AMCAS Application Timeline and When AMCAS Closes guide, and my guide to the AMCAS primary application itself explains where recommendation letters fit into the rest of the primary.
What If You Do Not Have a Strong Science Professor Letter?
If you still have time before applying, I would treat this as something you can actively improve rather than assuming your application is doomed. Take an upper-level course where appropriate, participate meaningfully, attend office hours, ask thoughtful questions, and give the professor enough opportunities to know you as more than a name beside a grade.
You do not need to turn office hours into an obvious months-long campaign for a recommendation letter. The goal is to engage genuinely enough that somebody who eventually evaluates you has real experiences to draw from.
If you are already applying and a target school specifically requires a category of letter you cannot provide, contact that school rather than quietly substituting something else and hoping nobody notices. Some programs may allow alternatives in particular circumstances, while others may tell you that the stated requirement remains firm.
This is another reason I would identify recommenders months before AMCAS opens. Letter problems become much easier to solve when the deadline is still far away.
Is It Better to Have Three Strong Letters or Five Average Letters?
If three letters satisfy the school’s requirements and provide strong, complementary evaluations, I would take those over five letters in which the extra two add little information. Medical schools do not award points simply because you filled every available recommendation slot.
Every additional letter should earn its place by satisfying a requirement or showing something meaningful that the existing letters cannot. A fifth letter from another physician saying you were pleasant to shadow is unlikely to add much if a clinical supervisor already provided a detailed account of your patient interactions over two years.
Pay particular attention to schools that tell you exactly how many letters they want. Tulane, for example, currently prefers a maximum of three and warns applicants that additional letters may not all be read, while Florida sets its own maximum despite AMCAS allowing applicants to create more entries.
How Long Should Someone Know You Before Writing a Medical School Letter?
There is no magic number of months that suddenly makes a recommender qualified. The more important question is whether the amount and quality of interaction gave that person enough direct evidence to write a detailed evaluation.
A professor who taught a small discussion-intensive course for one semester and interacted with you every week may know you better than a physician you technically shadowed for a year but saw only once every month or two. A research mentor who supervised you through multiple projects over two years may have an even deeper view.
The AAMC explicitly asks writers to explain how long they have known an applicant and the capacity in which they interacted, which tells you that admissions committees care about the context behind the evaluation rather than simply reading the praise in isolation.
Does Your Medical School Letter Writer Need to Be a Doctor?
No. Medical schools routinely receive letters from professors, research mentors, employers, supervisors, advisors, and other people who are not physicians.
A letter writer’s profession should make sense relative to the part of your application they are evaluating. I would expect a professor to comment meaningfully on academics and intellectual engagement, a research mentor to discuss scientific work, and a clinical supervisor to have a better view of your behavior in a healthcare environment.
You are assembling evidence about several dimensions of your candidacy, not collecting autographs from physicians.
Can a Professor Who No Longer Works at Your College Write Your Letter?
Potentially, yes. What matters most is whether the person is an acceptable writer under the school’s rules and can still provide a strong evaluation based on the relationship you had.
Faculty change institutions, retire, and move into different roles all the time. If a professor taught you closely and remains willing to write a detailed recommendation, changing employers does not erase the experiences they had with you.
For unusual logistical circumstances, follow the current AMCAS instructions for identifying the writer and associated institution rather than guessing. The administrative details of a letter are much easier to resolve than replacing a genuinely strong long-term recommender.
How Should You Ask Someone to Write Your Medical School Letter?
Ask whether the person would feel comfortable writing you a strong recommendation for medical school, and give them enough time and information to do the job well. I prefer that wording because it gives someone a graceful opportunity to decline if they cannot provide the kind of enthusiastic evaluation you want.
Once they agree, make their job easier. Depending on your relationship and what they request, you might provide your CV or résumé, transcript, personal statement draft, activities information, deadlines, submission instructions, and a reminder of meaningful projects or experiences you shared.
You can also send them the AAMC’s letter-writer guidelines because those guidelines show exactly the kind of direct observations and contextual information medical schools find useful. You are not telling your recommender what to write; you are giving them the resources to make their own evaluation as informative as possible.
When Should You Start Choosing Medical School Letter Writers?
I would start identifying possible writers well before the spring when you submit your application. During the fall and winter before applying, you should have a fairly good idea of which professors, mentors, PIs, physicians, or supervisors know you well enough to become potential recommenders.
That gives you time to review school requirements, continue developing genuine relationships, and ask early enough that nobody feels rushed. I place letter planning in the months before AMCAS opens in my complete month-by-month medical school application timeline because waiting until secondaries arrive is unnecessarily late.
You also do not need to wait until every letter has been uploaded before submitting AMCAS. My AMCAS timeline guide explains the difference between requesting letters, receiving them, submitting the primary, entering verification, and eventually becoming complete at each medical school.
Who Should Write Your Medical School Letters? My Final Advice
If I were helping a friend choose their letter writers, I would start by opening the admissions requirements for every medical school on their list. I would identify the most restrictive academic requirements first, make sure we had eligible people to satisfy them, and only then compare the strength of the possible writers.
Among eligible people, I would favor the professor, research mentor, physician, employer, or supervisor who has actually spent enough time with you to describe specific moments. I want the person who saw you struggle with something and improve, who watched you take feedback without becoming defensive, who trusted you with greater responsibility, who saw how you treated classmates or patients, or who can explain why you stood out among the other students they have taught.
Then I would look at the letters as a group. Your professors do not need to duplicate your transcript, your physician does not need to repeat your personal statement, and five writers do not need to tell admissions that you are hardworking in five slightly different ways. The strongest collection gives the committee multiple independent pieces of evidence about who you are.
When I think back to the professors, physicians, and research mentors who became letter writers for me, the relationships were built through time and actual work together. I did not have to convince someone who barely knew me that I was worth recommending because the people I asked had already had opportunities to watch me learn, work, make mistakes, improve, and contribute.
That is the standard I would use for your own application. Meet the school’s requirements first, then choose evidence over prestige and depth over titles. If somebody can tell an admissions committee something meaningful about you that the rest of your application cannot show on its own, you have probably found the kind of person you want writing your medical school letter.