Letters of Recommendation

Letters of recommendation/evaluation are an important part of your application to professional school. During the application process, the first opportunity that schools have to learn about you is on paper. They have the application essay you write for them and they have your letters.

The letters need to be as detailed as possible. They need to show that the letter writer truly knows you. If the letter writer can only comment on the grade you received in class--that letter has not helped your application. Professional programs know your grades.

This means that you need to put effort into building a relationship with your letter writers. Whether they are faculty or other recommenders, you need to spend time having conversations with these future letter writers giving them a chance to get to know you as a person.

The letters you will need varies by the type of professional program to which you are applying and also the particular schools at which you are applying. You need to make sure you have thoroughly researched this BEFORE you apply.

Also, make sure you have asked letter writers about writing a letter BEFORE you put their name on an application. It is not cool for them to receive an email from an application service requesting a letter of recommendation which you have never even talked to them about it. Rude! Don't do this.

Remember that if you have questions about your letters, check a school's website first to make sure you can't find the answer there. If you cannot, then give their admissions office a call and VERY POLITELY ask your questions (they track all interactions with students so remember the politeness factor).

General Letter Information

For medical and dental school you can collect your letters through the Pre-Professional Advising letter service (see the Learning Center section on that), but for other fields your letter writers will need to submit your letters directly to your application service. Why? Those applications require the letter writer to answer some questions about you as an applicant. They have to rank you in terms of writing ability, oral communication, thinking skills, etc. So you will end up entering your letter writers name into the application and the system will email them an access code so that they can enter the system, answer the questions and upload their letter.

*Always ask your letter writers to save their letters. At the end of the application year, the letters are deleted from application systems. For those using the Pre-Professional Advising letter service, we still have your letters and you are covered. For all others, you have to start again with collecting letters.

Often 1-2 Science Faculty Letters

  • Some schools really mean biology, chemistry or physics when they say science faculty
  • Some schools mean lecture faculty and not lab faculty
  • Some schools do not think of engineering, kinesiology, nutrition, and other areas as science (you get about a 50:50 split). If you can, split the difference if you are in one of these majors. Get one letter from your major and one that is biology, chemistry, or physics.

1 Non-Science Faculty Letter

  • This is generally a social science or humanities faculty letter
  • If you want to use an engineering letter in this category, you cannot use engineering as a science faculty as well.

Personal Letter

  • This is a letter from someone who has seen you in action in a non-classroom setting such as research, volunteer work, shadowing, or a job.
  • This is NOT a character witness letter from your neighbor commenting on what a nice person you are.

Other Possible Required Letters

Professional in the Field

  • Some schools want a letter from someone you have spent time with clinically to show that you have spent time in clinical settings and know what you are getting into professionally.
  • Some fields like physical therapy and occupational therapy have a document to verify clinical hours that are part of the online applications (PTCAS and OTCAS). You will need to have these signed for some programs that you might be applying to.




Law schools vary a bit in what they ask for, but generally you should be able to find several letters that will please all the schools to which you are applying.

Be sure to talk to all of your letter writers BEFORE you enter their names into your Credential Assembly Service (CAS) so that the system does not email them asking for a letter before you have told them about it. This is rude.

Your letters will be housed in the CAS system for 5 years. This does not mean that all schools will be happy with 5 year old letters if you are applying toward the end of your CAS lifespan. So you will want to update letters along the way.

More information on Law School Letters.

Asking for letters can be daunting. Many of your letters will come from faculty who are very accomplished people. Still, they started as students--just like you. And you aren't asking for a kidney. Writing for letters is part of the job. A few tips:

  • Don't ask as they are prepping to start class--make an appointment to go meet with them.
  • Go in prepared. Take a resume. Give them a timeline. Know the instructions for what they will need to do. Make it as easy for them as possible.
  • Check in with them a couple weeks later to see if they need additional information.
  • Once the letter is submitted, write a Thank You note. While writing recommendations if kind of part of the job, it still takes a lot of extra time.
  • Let them know what happens with your application. This is what makes working in education so rewarding!

Learn more tips about Requesting Letters of Evaluation.


Pre-Professional Advising offers a letter service for students applying to medical and dental school. It opens in January each year for those applying that spring/summer.

Read more about the benefits and how it works: 2022 Pre-Professional Advising Letter Service.

Sign up for the service here.

If you need a letter for a field other than medical or dental school and would like something to be able to give to your letter writer to provide some guidance to them about what to include, this Letter Writer Guide can help.

Letter Service FAQs

  • Do I need to have confirmed with my letter writers before I sign up? 
    • No. You need to enter names of writers you've either asked or plan to ask when you sign up. If you need to make changes later to the list of writers, you can. Just email preprofessional@purdue.edu and let us know who to remove and/or add to your list. Don't fill out the sign up survey again.
  • Does PPA send a link to my letter writers so they can submit their letter?
    • No. When you sign up for the letter service, we send you a confirmation email. Attached to that email is a Letter Writer Handout. You give that handout to your letter writers. It explains to them how they submit the letters to us (by email or regular mail). If you do not give this handout to your letter writer, they will not know how to submit their letter, so it is very important for you to do this step.
  • Can I tailor letter packets to individual schools? What if one school wants 3 letters and another school wants more?
    • No. A single packet is created with all of the letters included in it. That packet is uploaded to the letter service and the schools you apply to have access to it. Application services don't allow for multiple packets to be uploaded - only one. Schools understand this. They realize there may be letters in the packet that are intended for another program. Don't panic if a school says it only wants 3 letters and there are 5 in your packet, for example. Schools will either ask you at the secondary application stage to indicate which letters in the packet you are using for their application, or they'll read all of the letters and select those that satisfy their requirements for the evaluation of your application.
    • It is still YOUR responsibility to research the letter requirements of the schools you are applying to and make sure those requirements are met by the letters in the packet.
  • How do I fill out the Letter of Evaluation section of my application? 
    • Read the confirmation email that was sent to you after you signed up for the letter service. Instructions are included in that email.
  • A school I'm applying to accepts a committee/pre-health advisor letter. Does Purdue offer such a letter?
    • No, and this will not negatively impact your application. The school will indicate what type of letter you should substitute (often, it's another science faculty letter).
  • Am I notified every time PPA receives one of my letters?
    • No. After the writer submission deadline (May 27, 2022) you can email preprofessional@purdue.edu and ask for an update on what letters we have received and we'll let you know. If we have not received a letter at that time, you can email the writer and remind them to submit the letter to PPA. 
  • When will PPA upload my letters?
    • Read the confirmation email that you were sent when you signed up for the letter service to remind yourself of the steps you must complete in order for our office to be able to upload your packet to the application service. 
  • I'm not applying to medical school or dental school. Can PPA still collect my letters?
    • No. We are only able to upload letters packets to medical and dental school application services. If you are applying to other types of programs, your letter writers will need to upload their letters directly to your application. Consider looking into Interfolio as an option.
  • I am reapplying and I want to use the letters on file. Do I need to sign up for the letter service again?
    • Yes. Fill out the form to sign up for this year's letter service, and answer "yes" to the question that asks if you've used the service in the past. Additional questions will be asked about the letters we have on file. 
  • You have my medical/dental school letters. Can you submit them to other programs, like a postbacc program, masters program, PhD program, etc?
    • No. We will only submit medical/dental school letters to medical/dental school application systems. Consider asking your letter writers to write a different version of their letter for these other purposes and use Interfolio for those applications, if possible.
  • I have other questions!