What PhD Programs Look for in Applicants: What Actually Matters
By Ya'el Courtney, PhD | Stanford Postdoc, Harvard PhD in Neuroscience
Last updated: March 2026
I get some version of this question from almost every student I work with: "What are PhD programs actually looking for?" Usually they're asking because they've been told conflicting things. One mentor says GPA is everything. Another says it barely matters. Someone on Reddit says you need three publications to be competitive, and someone else got into a top program with zero.
After going through this process myself (I applied to seven biomedical PhD programs and was admitted to all seven), serving on the admissions committee for Harvard's PhD Program in Neuroscience, and coaching dozens of applicants over the past several years, I can tell you: there is no single formula. But there are clear patterns in what makes an applicant competitive, and most of them aren't what people expect.
Here's what actually matters, roughly in order of importance.
Research Experience
This is the big one. It's non-negotiable for biomedical PhD programs. The committee wants to know that you understand what doing research actually looks like day to day, that you've spent real time in a lab, and that you've worked on a project with enough depth to talk about it meaningfully.
You do not need to have published a paper. You do not need to have three or four different lab experiences. What you need is at least one experience where you had a real role, worked on a defined question, used specific techniques, and can articulate what you did, what you found (or didn't find), and why it matters. Quality and depth beat quantity every time.
If you're an undergrad, I recommend getting into a lab by your sophomore year if possible. If that ship has sailed, don't panic. Look into funded summer research programs (REUs like AMGEN, BP-ENDURE, SURF, Leadership Alliance) or post-baccalaureate research positions. The NIH IRTA postbac program and Harvard's Research Scholar Initiative are both excellent. About half the students in my PhD program took a gap year or two to get more research experience before applying, and they were just as competitive as people who applied straight from undergrad.
The key thing admissions committees are looking for is evidence that you know what you're getting into. A PhD is five to seven years of working independently on hard problems that nobody has solved before. That's a very different experience from doing well in courses. Programs want to see that you've tasted that and you're coming back for more.
Letters of Recommendation
Strong letters of recommendation are absolutely critical, and I don't think most applicants appreciate how much weight they carry. Your letters are the admissions committee's way of confirming that everything you've told them about your research experience is true, and they go well beyond that. A great letter gives the committee a sense of your personality, your work ethic, how you handle setbacks, and what you're like to work with in a lab.
You need three letters. Ideally, at least two should come from PIs who have supervised you directly in a research setting. The letter should be submitted by the PI of the lab, even if a postdoc or graduate student who worked with you more closely helps draft it. That's totally normal and happens all the time.
If you haven't had three research experiences, it's fine to ask a faculty member who knows you well from a course or mentoring relationship. What matters is that the person can speak specifically and positively about your strengths.
Here's the most important piece of advice I give about recommendation letters: when you ask someone to write one, ask them directly if they can write you a strong, positive letter of recommendation. If they hesitate, if they say something vague like "I can write you a letter," or if they seem uncertain, that's your signal to ask someone else. You will likely never see these letters, so this is your only chance to gauge whether the letter will help or hurt you.
If you're reaching out to someone you haven't worked with in a while, offer to catch them up on what you've been doing. A quick Zoom call or meeting where you remind them what you worked on, share your current goals, and tell them where you're applying can make a big difference in how specific and compelling their letter ends up being.
Your Statement of Purpose
Your statement of purpose is where you weave your transcript and CV into a cohesive narrative. It's your chance to convince the admissions committee that you are both committed to pursuing a PhD and capable of doing so.
The structure is fairly standard across programs, even when the prompts look different. You open with a brief framing of your motivation and commitment to your field. Then you walk through your research experiences, being specific about your personal role, your approach, your results, and why the work matters. You close with why you're excited about this specific program and which labs you'd be interested in joining.
The most common mistake I see is writing a statement that reads like a CV in paragraph form. Listing what you did without explaining why it mattered or what you learned from it. The other common mistake is being too vague. "I helped with experiments in a neuroscience lab" tells the committee nothing. "I developed a behavioral assay to test odor discrimination in mice and used calcium imaging to track how cortical representations changed with learning" tells them everything.
I've published my own successful Harvard statement of purpose and Yale statement of purpose with annotations, if you want to see what this looks like in practice. I also cover statement writing in depth in my coaching sessions.
Grades
Grades matter, but probably less than you think. I've seen students with 4.0 GPAs get rejected and students with 3.3 GPAs get into top programs. Your transcript needs to show that you can handle rigorous coursework, especially in courses relevant to your field. But once you clear that bar, other factors (especially research experience and letters) carry much more weight.
If you have a low grade in a specific course or a rough semester, that's not necessarily a dealbreaker. Many applications give you space to address inconsistencies, and your statement of purpose can provide context. What admissions committees care about is the overall trajectory. Did you improve over time? Did you perform well in the courses that matter most for the work you want to do?
If your GPA is a genuine concern, the best thing you can do is make sure the rest of your application is rock solid. Excellent research experience, specific and glowing recommendation letters, and a well-written statement of purpose can absolutely compensate for an imperfect transcript.
Standardized Test Scores (the GRE)
The GRE is increasingly irrelevant. Many top programs have dropped it entirely, including Harvard and MIT's neuroscience programs, which stopped considering GRE scores in 2019. The trend has only accelerated since then.
Before you spend time or money preparing for the GRE, check whether your target programs even require it. Many don't. If one or two of your programs still ask for it, it's worth preparing (consistent practice over a couple of months is the way to go), but know that it's rarely a make-or-break component of your application. A strong GRE score won't get you in on its own, and a mediocre one is unlikely to keep you out if the rest of your application is strong.
Fit
This one is harder to quantify but it matters a lot. "Fit" means: does this applicant make sense for our specific program? Are there faculty here who would want to mentor this student? Does this person's research trajectory align with what we do? Would they thrive in our environment?
This is why I always tell applicants to make sure there are at least three PIs they'd be genuinely excited to work with at any program they apply to. If you can't name three, the program probably isn't a great fit for you, and the admissions committee will sense that too.
Fit also shows up in the specificity of your application. When you mention labs you're interested in and explain why, when you reference specific resources or training opportunities the program offers, when your research interests clearly align with the department's strengths, that all signals fit. Generic statements like "I am interested in your prestigious program" signal the opposite.
Everything Else
Teaching experience, science communication, outreach, mentoring, leadership, DEI involvement: these are all genuinely valuable and can strengthen your application. But they are supplementary. No amount of extracurricular involvement will compensate for a lack of research experience. Think of them as things that can set you apart from other applicants who are equally strong on the core criteria.
If you've done meaningful work in any of these areas, absolutely include it. If you ran a tutoring program, organized a science outreach event, mentored younger students in your lab, or contributed to DEI initiatives in your department, those things tell the committee something real about who you are and what you'll bring to a program beyond your benchwork.
What About Publications?
I want to address this directly because it causes so much unnecessary anxiety. You do not need publications to get into a PhD program. Many excellent applicants have never published. Many applicants who do have publications were not first authors or played relatively minor roles.
If you have a publication, great. It's a nice line on your CV and it signals that you've been part of a project that made it to completion. But what the committee cares about much more than whether you published is whether you can talk about your research with depth and specificity. A student who spent two years on a project, can walk me through their approach, explain what worked and what didn't, and articulate what they learned from the process is far more compelling than a student who is third author on a paper but can't explain the methodology.
The Honest Truth
PhD admissions is not purely meritocratic. There are elements of luck, timing, and fit that are outside your control. A faculty member might be looking for a very specific type of experience that year and not advertise it. A committee might have more qualified applicants than available spots. Your application might land on someone's desk on a bad day.
What you can control is putting together the strongest, most authentic application possible. Get meaningful research experience. Build genuine relationships with people who can write you strong letters. Write a statement that sounds like you, not like a template. Apply to programs where your interests actually align with the faculty. And give yourself enough time to do all of this well.
If you don't get in on your first try, that is not a reflection of your potential as a scientist. Some of the best PhD students I know took a year or two after undergrad to strengthen their applications, and they're thriving.
Want personalized feedback on your PhD application? I offer one-on-one coaching for statement of purpose writing, application strategy, and interview prep. If you're not sure where you stand as an applicant, a free consultation is a good place to start.
