Test complexity categories. Source: 42 CFR 493.5
Moderate vs high complexity scoring. Source: 42 CFR 493.17
CLIA certificate program. Source: CMS CLIA
Every U.S. site that tests human specimens to diagnose, prevent or treat disease needs a CLIA certificate, and the right certificate depends on the most complex test you perform. This page explains the three complexity categories, the five certificate types, and how to choose.
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1. Waived tests (§493.15): simple tests with a low risk of an incorrect result, cleared by the FDA for home use or waived under FDA criteria
2. Moderate complexity (§493.20), which includes the provider-performed microscopy (PPM) subcategory (§493.19).
3. High complexity (§493.25).
The FDA categorizes commercially marketed test systems. You can look up a test's complexity in the FDA CLIA database by test name, analyte or manufacturer (see our FDA CLIA test lookup page). If you modify an FDA-cleared test, or run a test the FDA hasn't categorized (such as a laboratory-developed test), it is treated as high complexity
The FDA scores each nonwaived test on seven criteria, each rated 1 (lowest), 2 or 3 (highest):
Knowledge needed to perform the test
Training and experience
Reagent and materials preparation
Characteristics of operational steps
Calibration, quality control and proficiency testing materials
Test system troubleshooting and equipment maintenance
Interpretation and judgment
A total score of 12 or less is moderate complexity. A score above 12 is high complexity.
Certificate of Waiver (CoW): waived tests only. Not routinely surveyed, but CMS may inspect, for example to investigate a complaint. See CLIA waiver requirements.
Certificate for Provider-Performed Microscopy Procedures (PPM): PPM procedures performed by a physician, midlevel practitioner or dentist, plus waived tests. Not routinely surveyed. See PPM certificate.
Certificate of Registration: issued to a new nonwaived lab so it can start testing until the survey that determines compliance. It is temporary.
Certificate of Compliance (CoC): issued after a state agency survey shows the lab meets CLIA. Surveys occur every two years.
Certificate of Accreditation (CoA): issued when the lab is accredited by a CMS-approved accrediting organization (such as CAP, COLA, The Joint Commission, AABB, A2LA, ACHC or ASHI). The accreditor surveys on its own cycle (every two years), and CMS may perform validation surveys. See CAP and COLA accreditation.
CLIA certificates are generally valid for two years and must be renewed by paying the certificate fee CMS bills.
Match the certificate to the highest complexity test you perform:
Waived tests only → Certificate of Waiver
Waived plus PPM procedures (performed by qualified providers) → PPM certificate
Any moderate or high complexity test → Certificate of Registration first, then Compliance or Accreditation
Your choice also sets your personnel requirements. A Certificate of Waiver lab has no CLIA personnel qualification standards beyond following manufacturer instructions; nonwaived labs need a qualified director, technical consultant or technical supervisor, clinical consultant and testing personnel (Subpart M).
You apply with Form CMS-116, submitted to the State Agency for the state where the lab is located. The same form is used to change certificate type, for example moving from Waiver to Compliance when you add a moderate complexity analyzer. Do not perform the new testing until the change is approved. See our CMS-116 how-to.
Some states require their own laboratory license in addition to CLIA, and New York and Washington operate CLIA-exempt state programs. Check our state license guide.
Can a Certificate of Waiver lab run a moderate complexity test?
Is PPM moderate complexity?
No. The lab must first apply for the right certificate (Registration, then Compliance or Accreditation) using Form CMS-116 and meet nonwaived requirements.
Yes. PPM procedures are a subcategory of moderate complexity (§493.19), and a PPM certificate also allows waived tests.
How do I find a test's complexity?
How often are labs inspected?
Search the FDA CLIA database by test system, analyte or manufacturer. Modified or uncategorized tests are high complexity.
Labs with a Certificate of Compliance or Accreditation are surveyed every two years. Waived and PPM labs aren't routinely surveyed but can be inspected.
Sound Lab Consultants provides lab director and technical consultant services, inspection readiness and mock surveys, deficiency and sanctions response, new lab startup, and waived-to-moderate/high complexity upgrades.
Book a free 20-minute consultation, or start with a free CLIA readiness check.