ASCP MLS
Offered by ASCP Board of Certification (BOC)
MLS(ASCP) is the American Society for Clinical Pathology Board of Certification exam for Medical Laboratory Scientists. It is a computer-adaptive test of...
COMMUNITY
Study group
No public group yet
Start the first ASCP MLS study group so the next person who lands here has somewhere to join.
FORUMS
No discussions yet
Open the first ASCP MLS thread. Ask a question or share what you're studying.
Tutors
No tutors listed for this exam yet.
We’re building our network of trusted ASCP MLS tutors. Check back soon or join the community to connect with peers.
Not ready to host?
We’ll email you when someone else starts an ASCP MLS group.
ASCP MLS exam at a glance
Format
100 multiple-choice questions, computer adaptive (CAT); one best answer; items cannot be skipped
Duration
2 hours 30 minutes
Delivery
Pearson VUE test centers
Passing score
400 on a 100–999 scaled scale
Exam cost
$260 USD non-refundable application fee (MLS(ASCP); reduced pricing may apply in some countries)
Validity
Certification Maintenance Program (CMP) on a 3-year cycle
Prerequisites
Meet one published BOC route (accredited MLS program, or degree plus clinical experience/categorical certifications — see current route chart)
About the ASCP MLS certification
MLS(ASCP) is the American Society for Clinical Pathology Board of Certification exam for Medical Laboratory Scientists. It is a computer-adaptive test of 100 multiple-choice questions in 2 hours 30 minutes covering blood bank, chemistry, hematology, microbiology, immunology, urinalysis/body fluids, and laboratory operations.
The scaled passing score is 400 on a 100–999 scale. You must answer each item to continue; skipping is not allowed. Several education and experience routes exist — Route 1 is typically an NAACLS-accredited MLS program plus a baccalaureate degree.
Who it’s for: Clinical laboratory science graduates and experienced laboratorians seeking MLS(ASCP) certification for hospital and reference-lab roles.
Official exam page· Details verified September 2026
Exam details can change. Always confirm current requirements, fees, and exam policies with the certification provider before registering.
What the ASCP MLS exam covers
- Blood banking17–22%
- Chemistry17–22%
- Hematology17–22%
- Microbiology17–22%
- Urinalysis and other body fluids5–10%
- Immunology5–10%
- Laboratory operations5–10%
How to study for the ASCP MLS
- 1Download the current MLS content guideline and study the seven content percentages, not a random Q-bank order.
- 2Rotate blood bank, chem, heme, and micro weekly — each is about one-fifth of the exam.
- 3Practice calculations and result correlation (disease states) rather than only instrument menus.
- 4Take CAT-style practice: you cannot skip, so build a first-answer discipline.
- 5File the application with documentation early; the $260 fee is non-refundable and routes are audited.
Turn your exam date into a ASCP MLS study plan
Tell us when you're taking the ASCP MLS and when you're available to study. We'll build a personalized schedule you can add to your calendar.
Build My Free ASCP MLS Study PlanASCP MLS — frequently asked questions
What is the ASCP MLS passing score?
A scaled score of 400 on the 100–999 scale. There is no published raw percentage because CAT difficulty adapts.
Is MLS the same as MLT?
No. MLT(ASCP) is a separate technician-level exam. MLS is the scientist-level credential with a different content outline and eligibility routes.