Question: What is CLS Certification and is Certification a Requirement for Clinical Laboratory Scientists (CLSs)?

Answer: CLS certification is a general term used to indicate that an individual has been trained, tested, and independently certified to work as a clinical laboratory scientist (CLS) or a medical laboratory scientist (MLS). There are three organizations that provide professional certifications in the field of clinical laboratory science: the American Society for Clinical Pathology (ASCP), American Medical Technologists (AMT), and the American Association of Bioanalysts (AAB).

Most employers require clinical laboratory staff be certified and there are 11 states that currently require CLSs and MLSs to attain licensure, a process that varies by state, but usually involves passing an ASCP, AMT, or AAB certification exam. To be eligible for CLS certification, individuals typically must hold a bachelor’s degree or post-baccalaureate certificate from a training program accredited by the National Accrediting Agency for Clinical Laboratory Sciences (NAACLS) and complete at least one year of qualifying clinical experience working as an assistant or a technician in a clinical medical laboratory. To learn more about certification in clinical and medical laboratory science, continue reading below.

What is Clinical Laboratory Science?

Clinical laboratory science, also referred to as medical laboratory science, is the field of professional healthcare practice in which various diagnostic tests are administered and analyzed in order to assess patient health, identify illness, and facilitate further medical treatments. Clinical and medical laboratory staff is typically comprised of generalists and specialists who are responsible for conducting bacteriological, biochemical, hematological, immunological, and microbiological testing and analysis of blood and other biological specimens in order to detect the presence of infectious agents, cellular abnormalities, metabolic disorders, nutritional deficiencies, and other signs and symptoms of illness and disease.

The responsibility for coordinating and orchestrating this diagnostic work is commonly handled by a department of pathology at a clinic, hospital, medical center, or other type of patient-care facility. Departments of pathology generally employ medial laboratory assistants (MLAs), medical laboratory technicians (MLTs), and medical technologists (MTs), the latter of which are also referred to as clinical laboratory scientists (CLSs) and medical laboratory scientists (MLSs).

The American Society for Clinical Laboratory Science (ASCLS), describes medical laboratory science professionals as, “healthcare detectives, uncovering and providing laboratory information from laboratory analyses that assist physicians in patient diagnosis and treatment, as well as in disease monitoring or prevention.” The staff of clinical laboratory facilities, as noted above, includes three tiers of clinicians: MLAs, who can begin work that involves preparing and processing specimens after completing high school and supervised training in a medical laboratory; MLTs, who are typically trained in two-year associate degree programs and are qualified to collect biological samples, conduct basic diagnostic tests, and report the results of those tests; and MLSs/CLSs, who typically hold a bachelor’s degree and are qualified to conduct more complex tests, analyze data, and interpret the results.

In addition, there are CLS/MLS specialists who have training and may hold certifications in areas such as blood banking, chemistry, cytogenetics, cytotechnology, hematology, microbiology, molecular biology, and phlebotomy.

CLS Certification Agencies and Credentials

There are three nationally recognized organizations that provide professional certifications in clinical/medical laboratory science. The American Society for Clinical Pathology, or ASCP, offers credentials with the designations Medical Laboratory Scientist (MLS), Medical Laboratory Technician (MLT), and Medical Laboratory Assistant (MLA) through its Board of Certification (BOC). ASCP BOC certifications are the most common credentials sought by medical laboratory professionals in the US. These certifications are assigned based on education level: high school graduates with sufficient training qualify for MLA certification; associate degree graduates with sufficient training qualify for MLT certification; and bachelor’s degree graduates with sufficient training and experience may qualify for MLS certification. The ASCP also offers credentials for MLSs and MLTs who have specialized training areas like phlebotomy, blood banking, cytogenics and cytotechnology, hematology, microbiology, molecular biology, and laboratory management.

American Medical Technologists (AMT) and the American Association of Bioanalysts (AAB) are the two other organizations that offer credentials for MLSs, MLTs, and MLAs. These certifications are similar to ASCP certifications, although AMT and AAB use different terminology and certification classification systems. While both organizations offer an MLT credential for medical laboratory staff with two years of training in an associate degree program, the clinical laboratory scientist credential offered by AMT and the AAB that is analogous to the ASCP’s MLS credential is a Medical Technologist (MT) credential. In order to qualify for AMT’s MT certification, candidates must hold a bachelor’s degree. However, the AAB allows candidates who hold an associate degree in laboratory science or medical technology to sit for its MT certification exam.

AMT has several additional credentials, including: Medical Assistant (RMA); Phlebotomy Technician (RPT); Medical Administrative Specialist (CMAS); Medical Laboratory Assistant (CMLA); and Certified Laboratory Consultant (CLC). The AAB’s Board of Registry (ABOR) provides additional credentials with the following designations: Medical Diagnostics Technologist (MDxT); Andrology Laboratory Scientist (ALS); and Embryology Laboratory Scientist (ELS).

CLS Certification Eligibility Requirements

Eligibility for professional credentials in clinical laboratory science varies by certification organization and by specialization. Candidates for the CLS generalist certifications offered by the ASCP, AMT, and AAB must meet specific education and professional experience requirements, as detailed in the sections below.

ASCP Certification

The ASCP’s CLS certification for clinical laboratory science general practice is the Medical Laboratory Science, or MLS (ASCP) certification. There are four ways to qualify to sit for the MLS (ASCP) examination and receive the ASCP’s MLS credential:

• Candidates without a Clinical Laboratory Assistant (CLA) or Clinical Laboratory Technician (CLT) certification from the ASCP may qualify for MLS certification if they hold a bachelor’s degree from a regionally accredited college or university and complete an NAACLS-accredited Medical Laboratory Science training program.
• Candidates who hold an ASCP CLT credential may qualify if they hold a bachelor’s degree from a regionally accredited college or university with 32 semester hours of coursework in chemistry and biology, and if they have worked for a minimum of two years in an acceptable clinical laboratory setting.
• Candidates who hold an ASCP CLA credential may qualify if they hold a bachelor’s degree from a regionally accredited college or university with 32 semester hours of coursework in chemistry and biology, and if they have worked for a minimum of four years in an acceptable clinical laboratory setting.
• Candidates who hold a bachelor’s degree from a regionally accredited college or university with 32 semester hours of coursework in chemistry and biology, may qualify after working for a minimum of five years in an acceptable clinical laboratory setting.

AMT Certification

AMT’s general-practice credential for CLSs is the Medical Technologist (MT) credential. In order to qualify to sit for AMT’s MT certification exam, candidates must meet one of the following criteria:

• A bachelor’s degree in medical technology/medical laboratory science from an accredited college university program with clinical laboratory experience in blood banking, microbiology, chemistry, and hematology.
• A bachelor’s degree in a field other than medical technology/medical laboratory science from an accredited college or university plus one year of approved clinical laboratory experience.
• A bachelor’s degree in a field other than medical technology/medical laboratory science from an accredited college/university plus the completion of an accredited MLT training program or a U.S. military MLT training program.

AAB Certification

The AAB’s general-practice credential for CLSs is the MT (AAB) certification, which is administered by the AAB’s Board of Registry (ABOR). Applicants for this credential must pass the MT (AAB) Basic Knowledge exam after meeting one of the following requirements:

• A bachelor’s degree from an accredited college or university with a major in chemical, physical, biological, or clinical laboratory science or medical technology.
• An associate degree from an accredited school with a major in laboratory science or medical technology.
• A minimum of 60 semester hours of college-level coursework from an accredited school with at least 24 semester hours of medical laboratory technology coursework or 24 semester hours of biology, chemistry, and medical laboratory science coursework.

Benefits of CLS Certification

In addition to demonstrating knowledge and proficiencies in core areas of medical laboratory science and technology, CLS certification provides general opportunities for career advancement in the field of medical laboratory science. Many employers require CLSs to hold at least one credential/certification at the MLS/MT level in order to perform certain laboratory tests, oversee junior laboratory staff, and/or analyze test results. In addition, there are currently 11 states in which licensure by a state board is required for clinical and medical laboratory scientists: California, Florida, Georgia, Hawaii, Louisiana, Montana, Nevada, New York, North Dakota, Tennessee, and West Virginia.

While licensure requirements vary by state, most states that have a licensure process require CLSs to be certified in order to attain licensure. MTs and MLSs who intend to practice in a state that requires licensure should contact their state board regarding eligibility requirements.

Sources and Resources for CLS Certification

More information about CLS certifications, including general-practice credentials and specialization credentials, is available from the certification agencies that administer the certification programs described above.

• The American Society for Clinical Pathology (ASCP) Board of Certification (BOC)
• American Medical Technologists
• The American Association of Bioanalysts (AAB) Board of Registry

Healthcare Programs FAQ Pages: