Medical laboratory certification: MLT vs MLS & jobs
ASCP is the main US certifier for lab staff. The MLT exam costs $235 and the MLS exam $260 as of 2026, and both credentials renew every 3 years.
What's medical laboratory certification?
Medical laboratory certification is a national credential that shows you've met the education and examination standards to run clinical lab tests, and in the United States most of it runs through the ASCP Board of Certification. ASCP issues 2 credentials. MLT (ASCP), Medical Laboratory Technician, sits at the associate level. MLS (ASCP), Medical Laboratory Scientist, sits at the bachelor level. You earn either one by qualifying under an eligibility route and passing a computer-based exam, then you keep it current every 3 years. Employers treat the ASCP credential as the standard hire requirement, and a dozen or so states build their own license on top of it.
MLT vs MLS
The difference between MLT and MLS is the degree behind it and the depth of work it certifies you for. Both run the same instruments and report patient results, but the MLS is a bachelor-level credential that covers more complex analysis and troubleshooting, and it usually pays more.
| MLT (ASCP) | Medical Laboratory Technician. Built on an associate degree or 60 semester hours plus an accredited MLT program, or on qualifying experience. Technicians run routine tests and operate analyzers, often under a scientist's supervision. |
|---|---|
| MLS (ASCP) | Medical Laboratory Scientist. Built on a bachelor's degree, usually paired with an accredited MLS program. Scientists cover the full test menu, resolve instrument and result problems, and take on lead and quality roles. You may still see the older MT (ASCP) title on veteran staff; it's the same scientist-level credential under a former name. |
If you're deciding where to start, the MLT is the faster, cheaper entry point, and it counts toward the MLS later through a dedicated route.
Who requires MLT or MLS
Hospital and reference labs require an ASCP credential on nearly every bench posting, because their accreditation and many state laws expect certified staff. In our US listings that covers medical laboratory scientists and medical laboratory technicians across chemistry, hematology, microbiology, blood banking, and molecular sections. Hospital labs, commercial and reference laboratories, blood banks, and outpatient clinics list MLT or MLS as required or preferred, and the level they ask for follows the job: a generalist bench role often accepts either, while a lead or specialist role asks for the MLS.
Requirements and eligibility
ASCP publishes several routes to each exam, and you've to satisfy every part of one route rather than mixing pieces from different ones. These are the common US ones.
- MLT, program route. An associate degree or 60 semester hours of college credit, including set chemistry and biology hours, plus a Medical Laboratory Technician program accredited by NAACLS or ABHES completed within the past 5 years.
- MLT, experience route. The same academic credit plus qualifying full-time clinical lab experience across the main sections, for people who trained on the job rather than through a formal program.
- MLS, program route. A bachelor's degree from an accredited college plus a NAACLS-accredited Medical Laboratory Scientist program.
- MLS, technician route. A bachelor's with the required science coursework, a current MLT (ASCP) certification, and qualifying clinical experience. This is the standard path up from technician.
You don't always need a formal program. The MLT has an experience route, and the MLS lets certified technicians qualify through the technician route. What you do need is the specific coursework and clinical time your chosen route names, so read the route requirements on the ASCP site before you apply. ASCP retired the old CLA-based MLS and MLT routes in 2023, so a lab-assistant credential no longer qualifies you on its own.
How to go from MLT to MLS
You move from MLT to MLS by earning a bachelor's degree and qualifying under an MLS route, most often the one written for certified technicians. You keep your MLT (ASCP) active, finish a bachelor's with the science hours ASCP lists, log the required clinical experience, and then sit the MLS exam. You don't resit the MLT exam, and your years on the bench count toward the experience the route asks for. Many working technicians do this through an online MLS completion program while they stay employed.
Cost, format, and renewal
The figures below are current as of 2026, from the ASCP Board of Certification. Both application fees rose by $10 on January 1, 2026.
| MLT exam fee | $235 for the US application (ASCP, 2026) |
|---|---|
| MLS exam fee | $260 for the US application (ASCP, 2026) |
| Format | Computer adaptive test at a Pearson VUE center, 100 questions, 2 hours 30 minutes |
| Passing score | Scaled score of 400 on a 0 to 999 scale |
| Result | Preliminary pass or fail on screen when you finish |
| Validity period | 3 years |
| Renewal requirement | 36 continuing-education points per 3-year cycle through the Credential Maintenance Program (CMP), for both MLT and MLS |
| Renewal mark | Once you complete the CMP you add a superscript CM, written MLS(ASCP)CM |
| Issuing body | ASCP Board of Certification (ascp.org) |
Submit your CMP declaration in the last 3 months before your credential expires, and no later than 30 days before it lapses. A per-credential maintenance fee applies; if you hold more than one ASCP credential you can renew them together at a reduced rate.
Certification and your state license
Certification is national, and about a dozen states add a separate personnel license you also have to hold. California, Florida, New York, Hawaii, Louisiana, Montana, Nevada, North Dakota, Tennessee, and West Virginia license lab personnel, and Puerto Rico does too. Most of them accept your ASCP certification as the qualifying standard and then charge their own fee and continuing-education rules on top. California is the outlier: it runs its own license and doesn't treat any national certification as enough on its own, so you apply to the state directly and sit its law exam. Check the practice act in the state you'll work in, because where a license is required the employer needs both it and your ASCP credential.
How to get certified
- Pick your level and route: MLT if you're starting from an associate program or bench experience, MLS if you hold or are finishing a bachelor's.
- Complete the degree, accredited program, or clinical experience your route names, and gather transcripts and verification.
- Create an account and apply through the ASCP Board of Certification, paying the $235 (MLT) or $260 (MLS) fee.
- Once ASCP approves your eligibility, schedule your exam at a Pearson VUE center inside your 3-month testing window.
- Pass the computer adaptive exam, a scaled 400, and get your preliminary result on the spot.
- Apply for a state license if your state requires one, then track 36 CE points per 3-year cycle to keep the credential active.
Demand for MLT and MLS on MedJobList
MLT or MLS is named in 200 of the active US openings we track right now. Those roles are in hospital, reference, and blood-bank laboratories, where postings ask for the ASCP credential at the level the bench calls for. You can browse them in the section below, or filter the full job list by MLT or MLS yourself.
On the job
Keep your CMP cycle logged, because an expired credential can pull you off the bench schedule and take weeks to reinstate. Employers verify ASCP status through the registry, so a lapse is easy to spot. Ask at onboarding who covers continuing education and license renewal: many hospital labs pay for CE courses and reimburse the state license fee, so raise it before you pay out of pocket.
