The Medical Laboratory Technician, MLT(ASCP), certification exam measures the laboratory knowledge and applied skills required of entry-level medical laboratory technicians. The computer-adaptive exam covers blood banking, chemistry, hematology, immunology, microbiology, urinalysis and other body fluids, and laboratory operations. This guide covers current eligibility routes, exam content, scoring, fees, testing procedures, retake rules, and certification maintenance.
What Is the MLT(ASCP) Certification?
The Medical Laboratory Technician, MLT(ASCP), credential is awarded by the American Society for Clinical Pathology Board of Certification (ASCP BOC).
Medical laboratory technicians collect, process, and perform routine laboratory testing on blood and other biological specimens. Their work provides information used by healthcare professionals to diagnose, monitor, and treat disease.
Laboratory areas may include:
Blood banking and immunohematology
Clinical chemistry
Hematology and hemostasis
Immunology
Microbiology
Urinalysis and body-fluid testing
Quality control, safety, instrumentation, and other laboratory operations
MLT certification and state licensure are not the same thing. Some states separately license laboratory professionals. Earning MLT(ASCP) certification does not automatically satisfy every state licensing requirement, so check the rules where you intend to work.
MLT vs. MLS
Medical Laboratory Technician and Medical Laboratory Scientist are related but different ASCP BOC credentials.
Typically associated with associate-degree-level laboratory education and routine testing in the major clinical laboratory disciplines.
A separate scientist-level credential that generally requires a bachelor’s degree and covers routine through more complex laboratory testing and problem solving.
Who Is Eligible for the MLT(ASCP) Exam?
You must satisfy the requirements of at least one current ASCP BOC eligibility route before you can take the examination.
Route 1: Accredited MLT Program
You need:
An associate degree from an accredited college or university or at least 60 semester hours / 90 quarter hours of accredited college credit
Successful completion of a NAACLS- or ABHES-accredited Medical Laboratory Technician program within the previous five years
Route 2: Discontinued
Route 2 is no longer available. The former MLT Route 2 required a valid CLA(ASCP) certification. ASCP BOC discontinued this route effective January 1, 2023.
Route 3: U.S. Military Laboratory Training
You need:
An associate degree or at least 60 semester hours / 90 quarter hours of accredited college credit
At least 6 semester hours of chemistry and 6 semester hours of biology
Successful completion of a 50-week U.S. military medical laboratory training course within the previous 10 years
Military applicants must provide official documentation of their applicable military occupational specialty or training.
Route 4: Clinical Laboratory Experience
You need:
An associate degree or at least 60 semester hours / 90 quarter hours of accredited college credit
At least 6 semester hours of chemistry and 6 semester hours of biology
Three years of full-time acceptable clinical laboratory experience within the previous six years
The clinical experience must include work in all of the following areas:
You do not need three separate years in every individual laboratory area, but your qualifying experience must collectively cover all required disciplines.
Program substitution under Route 4: Successful completion of certain qualifying medical laboratory programs within the previous five years may substitute for one year of full-time clinical experience. Check the current ASCP BOC documentation requirements before applying.
International MLT Applicants
ASCP BOC also offers the separate MLT(ASCPi) international credential.
The eligibility routes for MLT(ASCPi) differ from those used for the U.S. MLT(ASCP) credential. Candidates educated and trained outside the United States, U.S. territories, and Canada should review the international requirements carefully before submitting an application.
MLT Exam Format
Every question has four answer choices with one best answer.
The MLT exam uses computerized adaptive testing (CAT). The computer adjusts the difficulty of later questions based partly on your performance on earlier questions.
You will still answer 100 questions. Unlike some adaptive exams that stop early, the standard MLT(ASCP) exam is designed as a 100-question examination. Your score is based on the difficulty and pattern of questions you answer across the exam.
You must answer each question before moving to the next one. You cannot skip an unanswered item, although you can flag questions and return to review them after answering all questions if time remains.
What Is on the MLT Exam?
The current ASCP BOC examination outline, revised in July 2025, contains seven major content areas.
| Content Area | Exam Percentage |
|---|---|
| Blood Banking | 15–20% |
| Urinalysis and Other Body Fluids | 5–10% |
| Chemistry | 20–25% |
| Hematology | 20–25% |
| Immunology | 5–10% |
| Microbiology | 15–20% |
| Laboratory Operations | 5–10% |
Blood Banking – 15–20%
The Blood Banking section covers immunohematology and transfusion medicine.
Topics include:
Blood donors, collection, processing, storage, and blood products
ABO, Rh, and other blood group systems
Blood group genetics
Antigens, antibodies, and antigen-antibody reactions
Pretransfusion testing and compatibility testing
Hemolytic disease and transfusion reactions
Serologic and molecular testing methods
Urinalysis and Other Body Fluids – 5–10%
This section covers physical, chemical, and microscopic examination of urine and other body fluids.
You should understand:
Urine formation and renal physiology
Physical and chemical urinalysis
Urine sediment microscopy
Renal and metabolic disease correlations
Cerebrospinal, synovial, serous, seminal, and other body fluids
Chemistry – 20–25%
Chemistry is one of the two largest content areas on the MLT exam.
Topics include:
Carbohydrates and glucose testing
Lipids and lipoproteins
Proteins and other nitrogen-containing compounds
Enzymes and heme derivatives
Electrolytes and acid-base balance
Blood gases
Endocrinology
Vitamins and nutrition
Therapeutic drug monitoring
Toxicology
Hematology – 20–25%
Hematology is also one of the highest-weighted areas of the exam.
You should understand:
Normal hematopoiesis and blood-cell development
Red blood cell morphology and anemias
White blood cell disorders and leukemias
Platelets and platelet disorders
Complete blood counts and hematology calculations
Hemoglobin testing
Hemostasis, coagulation disorders, and laboratory testing
Immunology – 5–10%
The Immunology section covers immune-system principles and diagnostic serology.
Topics include:
Innate and adaptive immune responses
Immunoglobulins and antigen-antibody reactions
Complement
Autoimmune disease and immunodeficiency
Transplantation
Infectious-disease serology
Serologic methods and interpretation of results
Microbiology – 15–20%
Microbiology covers laboratory identification and testing of medically important microorganisms.
Topics include:
Specimen collection, transport, processing, and rejection
Bacteriology
Mycobacteriology
Mycology
Parasitology
Virology
Culture media and incubation conditions
Staining and microscopic examination
Identification, susceptibility testing, and result reporting
Laboratory Operations – 5–10%
Laboratory Operations applies across essentially every area of laboratory medicine.
Topics include:
Preanalytical, analytical, and postanalytical quality assessment
Quality control and troubleshooting
Point-of-care testing
Regulatory compliance and proficiency testing
Laboratory and biological safety
Concentrations, dilutions, molarity, statistics, sensitivity, specificity, and predictive values
Manual and automated instrumentation and laboratory methodology
Study priority: Chemistry and Hematology can each account for as much as 25% of the exam. Blood Banking and Microbiology can each account for another 20%. Those four disciplines should make up a large portion of your study time, while still reviewing all seven content areas.
How Much Does the MLT Exam Cost?
The current MLT(ASCP) application fee is $235. The application fee is nonrefundable and nontransferable.
If you are found ineligible, fail to schedule within your eligibility period, miss your appointment, or need to reapply after an unsuccessful attempt, another application and fee may be required.
How Do I Apply?
1. Determine your eligibility route.
Compare your education, training, and clinical experience with the current MLT(ASCP) Route 1, Route 3, or Route 4 requirements.
2. Gather the required documentation.
This may include official transcripts, program-completion documentation, military records, or clinical-experience forms depending on your route.
3. Submit the ASCP BOC application.
Complete the online application and pay the $235 application fee.
4. Wait for eligibility review.
ASCP BOC evaluates the application and supporting records to verify that you satisfy your selected route.
5. Receive your Admission Notification.
Once you are made eligible, your ASCP account provides instructions for scheduling the certification examination.
6. Schedule with Pearson.
Select an available Pearson testing center and appointment within the eligibility period shown in your Admission Notification.
Choose your eligibility route carefully. Once an ASCP BOC application has been submitted, you cannot simply change the certification category or eligibility route on that application.
Where Is the MLT Exam Taken?
The MLT(ASCP) certification exam is administered at approved Pearson testing centers.
Once ASCP BOC approves your application, you receive an Admission Notification explaining how to schedule the exam. Available testing centers, dates, and times are shown through Pearson.
Schedule as early as practical because testing appointments are filled on a first-come, first-served basis.
Can I Reschedule My MLT Exam?
Yes, but you must contact Pearson at least one full business day, or 24 hours, before your appointment.
Your rescheduled appointment must remain within the eligibility period listed in your Admission Notification.
If you miss your appointment, cancel without rescheduling, or fail to test during your eligibility period, the application fee is not refunded or transferred and you generally must submit a new application.
What to Know Before Test Day
Arrive at the Pearson testing center approximately 30 minutes before your appointment.
Bring a current, unexpired ID containing your photograph and signature.
Make sure the first and last names on your ID match the names associated with your Pearson examination record.
An on-screen calculator is available during the examination.
Writing material for calculations is provided by the testing center.
Personal belongings are stored outside the testing room in a locker.
Phones, smartwatches, study materials, and other unauthorized electronic devices cannot be accessed during the exam.
How Is the MLT Exam Scored?
The MLT examination uses a scaled score from 100 to 999.
Passing score: 400. You must earn a scaled score of at least 400 to pass the ASCP BOC certification examination.
Because the exam is computer adaptive, there is no fixed number or percentage of questions that guarantees a passing result. Questions have different difficulty levels, and the CAT system continuously estimates your ability based on your responses.
This is why a score of 400 should not be interpreted as simply answering 40% of the questions correctly.
Field-test questions may also appear on the exam. They are used to evaluate possible future questions and do not contribute to your score, but they are not identified during testing.
When Will I Get My MLT Exam Results?
You will see a preliminary pass or fail result on the computer screen immediately after completing the certification examination.
The preliminary result is not your official credential confirmation.
ASCP BOC generally emails you within four business days to tell you that your official score report is available in your account, provided all required transcripts and other academic documentation have been received and processed.
All examinees should receive an official score report within approximately one week of testing.
You are not officially credentialed until your passing score report is available. The report includes your certification number and your three-year credential-cycle dates.
If you do not pass, your score report includes performance information for the exam’s content areas so you can identify stronger and weaker areas before retesting.
What Happens After I Pass?
Once your passing score report becomes available, you have officially earned the MLT(ASCP) credential.
Beginning in January 2026, newly credentialed ASCP BOC professionals receive a digital credential badge through Credly.
ASCP BOC no longer automatically mails wall certificates to newly credentialed professionals. Older information describing a certificate arriving several weeks after passing is no longer current.
What If I Don’t Pass?
You can apply to take the MLT examination again after an unsuccessful attempt.
Your next eligibility period begins no earlier than 30 days after your previous exam date.
You may attempt the exam five times under one eligibility route if you continue to meet that route’s requirements.
Each new examination attempt requires a new application and application fee.
After five unsuccessful attempts under one eligibility route, you must qualify under a different current eligibility route before attempting the certification examination again.
How Long Does MLT(ASCP) Certification Last?
Newly earned MLT(ASCP) credentials are issued on a three-year credential cycle.
To keep the credential valid, you must participate in the ASCP BOC Credential Maintenance Program (CMP).
MLT Credential Maintenance Requirements
The current MLT CMP requires 36 points during each three-year cycle.
| CMP Area | Points |
|---|---|
| Blood Banking | 2 |
| Chemistry | 2 |
| Hematology | 2 |
| Microbiology | 2 |
| Laboratory or Patient Safety | 1 |
| Medical Ethics | 1 |
| Other qualifying laboratory, immunology, molecular diagnostics, management, education, or related areas | 26 |
If you do not complete the required CMP process, a time-limited credential can expire and you may no longer cite the credential after your name until it is reinstated.
How Can I Prepare for the MLT Exam?
Use the official content percentages to determine where you spend your study time. Chemistry and Hematology carry the largest potential weights, followed by Blood Banking and Microbiology.
Because the exam is adaptive, memorizing isolated facts is not enough. The current content outline includes both theoretical and procedural questions that require you to interpret results, correlate laboratory findings with disease states, perform calculations, select appropriate laboratory procedures, and recognize quality-control problems.
MLT Study Checklist
Review ABO, Rh, antibody identification, compatibility testing, blood components, and transfusion reactions.
Know common urine chemistry findings, sediment elements, renal disorders, and other body-fluid testing.
Review clinical chemistry reference relationships, analytes, enzymes, electrolytes, acid-base balance, endocrine testing, toxicology, and therapeutic drug monitoring.
Practice identifying normal and abnormal blood-cell morphology and correlating CBC findings with disease states.
Review coagulation pathways, anticoagulants, hemostasis disorders, and coagulation testing.
Know immune-system principles, autoimmune disease, immunodeficiency, antigen-antibody testing, and infectious-disease serology.
Practice organism identification in bacteriology, mycology, parasitology, mycobacteriology, and virology.
Review quality control, specimen errors, proficiency testing, laboratory safety, and regulatory concepts.
Practice dilution, concentration, molarity, standard-curve, sensitivity, specificity, predictive-value, and basic statistical calculations.
Complete timed practice that requires application and troubleshooting rather than studying only fact-recall questions.
MLT Study Resources
Use these resources for additional MLT examination review and practice.
ASCP® and MLT(ASCP) are associated with the American Society for Clinical Pathology and its Board of Certification. ASCP BOC is not affiliated with StudyGuideZone or Mometrix Test Preparation and does not endorse these products or services.