McMaster University MSAF & Exam Deferral: Sick Note Guide

Last reviewed and updated: August 2026 by a licensed Canadian physician

McMaster's MSAF system lets you self-report for assessments worth less than 25%. But for finals and major assessments, you need medical documentation. Here's how to get it.

Updated August 2026, Current Ontario ESA and CPSO telemedicine standards.

McMaster University students can request a deferred exam through Mosaic with medical documentation. MedLetter provides same-day sick notes for $49 from CPSO-registered physicians that meet McMaster's Student Wellness Centre requirements. Available 24/7.


Who This Service Is For


MedLetter provides sick notes for students experiencing genuine short-term illness that prevents them from writing an exam or completing an assignment. Common qualifying conditions include:



    • Cold or flu with fever, body aches, or severe congestion

    • Food poisoning or stomach bug (vomiting, diarrhea)

    • Migraine or severe headache that makes concentration impossible

    • Sinus infection or ear infection

    • Strep throat or tonsillitis


Important: We do NOT provide notes for chronic conditions, mental health diagnoses, disability accommodations, or ongoing treatment. If your situation requires more than a 1-5 day absence, please see your campus health centre or family doctor.



September 2026 Back-to-School Alert


Fall semester starts in September and campus health centres will be overwhelmed with 3-5 week wait times. If you get sick during the first weeks of class and need to defer a quiz, midterm, or assignment, you will need medical documentation within 48-72 hours of your missed assessment.


Plan ahead: MedLetter delivers same-day sick notes for $49. No appointment needed. Available 7 days a week, including evenings when campus clinics are closed. New sick-note requests are temporarily paused while we review our service. We are not accepting new orders at this time.


McMaster's MSAF System: When You Do (and Don't) Need a Sick Note

McMaster University has one of the most student-friendly absence reporting systems in Ontario, the McMaster Student Absence Form (MSAF). But it has important limitations that many students don't understand until it's too late. Navigating the academic bureaucracy at McMaster can be incredibly stressful, especially when you are already dealing with the physical toll of an illness. Understanding exactly when the MSAF applies and when you must provide a formal medical certificate is crucial to protecting your academic standing. A single misunderstanding of these policies can result in a zero on a major assessment, which could jeopardize your GPA.

Understanding the MSAF

The MSAF allows you to self-report an absence without medical documentation for:

  • Assessments worth less than 25% of your final grade

  • A maximum of one MSAF per term (3 days maximum)

  • Absences due to illness, injury, or family emergency


While the MSAF is a fantastic tool for minor illnesses like a 24-hour stomach bug or a brief cold, it is strictly limited. Many students mistakenly believe they can use the MSAF for any missed work, only to discover that their specific situation falls outside the acceptable parameters. It is vital to remember that the MSAF is a one-time pass per semester for low-stakes assessments. Once you have used it, or if your assessment is heavily weighted, you are entirely responsible for providing legitimate medical proof of your inability to complete your coursework.

When the MSAF does NOT apply:

  • Final exams

  • Assessments worth 25% or more

  • If you've already used your MSAF this term

  • Labs, tutorials, or clinical placements (faculty-specific rules apply)


When You Need Medical Documentation at McMaster

You need a physician's note for:
1. Final exam deferrals, Submitted through the Registrar's Office. Final exams are the most critical assessments of the semester, and McMaster strictly enforces the requirement for medical documentation if you miss one. Without a valid sick note, you will receive a zero on your final exam, which often results in failing the course entirely.
2. Assessments worth 25%+, Requires a completed McMaster Medical Certificate. Midterms, major essays, and final projects often fall into this category. Because these assessments make up a significant portion of your grade, the university requires verifiable proof that your illness was severe enough to prevent you from completing the work.
3. Multiple absences in one term, After using your MSAF, subsequent absences require documentation. If you catch the flu in October and use your MSAF, and then get food poisoning in November, you will need a sick note for the second absence, regardless of the assessment's weight.
4. Extended absences (more than 5 days), Even with an MSAF, longer absences may require a note. If your illness lasts longer than the standard 3-day MSAF period, you must provide medical documentation to cover the extended time away from your studies.

McMaster's Medical Certificate Requirements

McMaster requires documentation that includes:

  • Physician's name and CPSO registration number

  • Date of assessment

  • Statement that the student was unable to attend the exam/complete the assessment

  • The period of incapacity


Note: McMaster specifically states that notes saying only "patient was seen on [date]" are not acceptable. The documentation must explicitly state that your medical condition prevented you from fulfilling your academic obligations. This is why having a properly formatted sick note from a licensed physician is absolutely essential. A vague note will be rejected by the faculty office, leaving you scrambling to get a revised note before the submission deadline expires.

Faculty-Specific Rules

  • DeGroote School of Business: Has its own absence policy; check with the DeGroote Academic Advising office. Business students often face strict participation and group work requirements, meaning absences can impact not only your grade but also your peers.

  • Faculty of Engineering: Strict attendance requirements for labs; medical notes required for any missed lab. Engineering labs are notoriously difficult to reschedule, and missing one without proper documentation can result in an automatic failure for that component of the course.

  • Faculty of Health Sciences (BHSc): Additional requirements for clinical placements. Health Sciences students must adhere to rigorous professional standards, and missing a clinical placement requires immediate and detailed medical documentation.

  • Faculty of Science: Standard MSAF rules apply for most courses, but specific lab components may have stricter requirements. Always check your course syllabus for detailed absence policies.


The McMaster Student Experience

McMaster's Hamilton campus serves 37,000+ students. During exam season, the pressure on local healthcare resources is immense. The reality of being a student in Hamilton is that accessing timely medical care can be a significant challenge, especially when you are feeling your worst.

  • The Student Wellness Centre wait times can exceed 4 hours. When you are battling a high fever or a severe migraine, sitting in a crowded waiting room for half the day is not only miserable but can also delay your recovery.

  • Hamilton walk-in clinics near campus (Main Street, Dundurn) are similarly overwhelmed. These clinics serve the broader Hamilton community as well as the student population, leading to long queues and unpredictable wait times.

  • Many students commute from Burlington, Oakville, or the GTA and don't have a local doctor. If you fall ill while on campus or in your student housing, traveling back to your hometown to see your family physician is often impossible.


Getting a Sick Note for McMaster

Option 1: McMaster Student Wellness Centre

  • Located in the Peter George Centre for Living and Learning (PGCLL)

  • Free for McMaster students but extremely busy during finals

  • May not have same-day availability, which is a critical issue when you have a strict 5-day deadline to submit your documentation.


Option 2: Hamilton Walk-In Clinics
  • Main Street Medical Centre, Dundurn Medical Centre

  • Expect 2-4 hour waits during peak times, exposing you to other illnesses while you wait.

  • Charge $20-50 for sick notes, plus the cost of transportation and the immense value of your lost study time.


Option 3: Online Sick Note (MedLetter)
  • Get your note within hours without leaving home. You can rest in bed and focus on getting better while we handle the documentation.

  • $49 flat fee includes physician assessment and documentation. This is comparable to the cost of a walk-in clinic note, but without the 4-hour wait and the hassle of traveling while sick.

  • Meets McMaster's medical certificate requirements. Our licensed physicians understand exactly what the university needs to approve your deferral.


When you compare the options, the choice is clear. A walk-in clinic might charge you $20 to $50 for the note itself, but you also have to factor in the 2 to 4 hours you will spend waiting in a room full of other sick people. That is time you could spend resting or studying for your other exams. With MedLetter, you pay a straightforward $49 fee and receive your documentation quickly and securely, without ever having to leave your dorm room or apartment.

New sick-note requests are temporarily paused while we review our service. We are not accepting new orders at this time.

McMaster's Highest-Enrollment Courses



    • PSYCH 1X03/1XX3 (Intro Psychology) — 1,200+ students

    • ECON 1B03/1BB3 (Intro Economics) — 1,000+ students

    • BIOLOGY 1A03/1M03 (Intro Biology) — 900+ students

    • MATH 1LS3/1LT3 (Calculus for Life Sciences) — 800+ students

    • CHEM 1A03/1AA3 (Intro Chemistry) — 800+ students


McMaster accepts medical documentation from any CPSO-registered physician through MSAF (McMaster Student Absence Form) for missed work under 3 days, or through your Faculty Office for longer absences. MedLetter covers exams, assignments, labs, and tutorials — $49 same-day.

Find your school: View all 52 Canadian universities and colleges with exam deferral guides.

Protecting your academic record is paramount. Do not risk failing a course because you could not get a doctor's appointment in time. The consequences of not having proper documentation are severe, including receiving a zero on your exam, failing the course, and potentially facing academic probation. A legitimate sick note is your best defense against these outcomes.

Frequently Asked Questions

Can I use an MSAF for a final exam at McMaster?
No. MSAFs cannot be used for final exams. You must apply for a deferred exam through the Registrar's Office with New sick-note requests are temporarily paused while we review our service. We are not accepting new orders at this time..

Will McMaster accept an online sick note?
Yes. McMaster accepts medical documentation from any CPSO-licensed physician. Online notes that include the physician's registration number and confirm incapacity are fully valid.

I already used my MSAF this term. What do I do?
You need medical documentation for any subsequent absences. Get a sick note from a physician (in person or online) and submit it to your faculty office.

How long do I have to submit a deferred exam request at McMaster?
You must submit within 5 business days of the missed exam. Don't delay, get your documentation immediately.

What happens if my sick note is rejected by McMaster?
If your note is rejected, it is usually because it lacks specific details, such as a clear statement of incapacity or the physician's CPSO number. MedLetter ensures all our notes meet these strict university requirements to prevent rejection.

How to Get Your Documentation

McMaster students: don't let a missed exam become an academic crisis. If you've already used your MSAF or need to defer a final, New sick-note requests are temporarily paused while we review our service. We are not accepting new orders at this time., $49 flat fee, delivered by email within hours. Our documentation meets McMaster's medical certificate requirements. Every minute you wait is a minute closer to the submission deadline. Secure your academic future today by getting the proper medical documentation you need to defer your exam and focus on your health.

Conclusion

McMaster's MSAF system is generous for minor assessments, but when it comes to finals and major coursework, you need proper medical documentation. Acting quickly is essential, the 5-business-day deadline for deferred exam requests means you can't afford to wait in a clinic queue. Online sick notes provide the fastest path to getting the documentation you need while you focus on recovery. Do not leave your grades to chance. Ensure you have the necessary proof of illness to protect your hard work and academic standing.

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