United States · Laboratory identifiers
CLIA number validator.
Check that a Clinical Laboratory Improvement Amendments (CLIA) identification number has the 10-character layout CMS publishes: two digits, the letter D, then seven digits.
The rule in one line: positions 1-2 are digits (the State code), position 3 is the letter D, and positions 4-10 are digits. Example shape: 45D0634589.
How to check a CLIA Number
- Type or paste the value. Spaces and hyphens are ignored and case does not matter.
- Press Check.
- Read the result: either the normalized value, or the exact rule it breaks.
Your input stays on your device
The check runs in your browser, inside an isolated frame on this page that has no network access. Nothing you type is uploaded to TNAADO or anyone else, and nothing is stored. The advertising on this page sits outside the frame and cannot see what you enter.
How a CLIA number is built
A CLIA identification number is the 10-character alphanumeric identifier CMS assigns to a laboratory certified under the Clinical Laboratory Improvement Amendments of 1988. The CMS CLIA Certification Quick Start Guide (March 2026) describes it as a "unique 10-character alphanumeric CLIA Identification Number" that you use to pay certification fees and to communicate with your State Agency or CMS.
The layout comes from the CMS State Operations Manual, chapter 2, in the section on supplier identification numbers: the first two characters identify the State in which the facility is located, the third is an alpha character identifying the type of facility, and the remaining seven are the unique facility identifier. For CLIA laboratories the third character is D. The same manual uses other third-position letters for other supplier types (for example C for ambulatory surgical centers, J for independent physical or occupational therapists and X for X-ray facilities), which is why a number with the right length but a different third letter fails here.
This page applies exactly that layout and nothing more. It does not know which two-digit State codes are currently in use and it does not know whether the last seven digits belong to a real laboratory.
Worked example (shape only): 45D0634589 has 10 characters. Characters 1-2 are 45 (digits, so the State-code position is satisfied), character 3 is D (the CLIA laboratory letter) and characters 4-10 are 0634589 (seven digits). It passes. Change the D to C and it fails with a message explaining that C is used for a different supplier type; drop the last digit and it fails on length.
Method
The check is a fixed set of format rules applied to the text you type, after upper-casing it and removing spaces and hyphens. There is no database, no estimate and no assumption about who you are: the same input always gives the same answer, and every rule is traceable to the sources below.
What this does not cover
- Whether the number was ever issued, is current, or belongs to the lab you are dealing with. Use the CMS QCOR CLIA laboratory lookup or your State Agency for that.
- Which State a two-digit code maps to, or whether it is a valid code.
- Certificate type (waiver, compliance, accreditation) or the tests a lab may run.
- Any other CMS provider identifier such as a CCN or an NPI.
Frequently asked questions
How many characters is a CLIA number?
Ten. CMS describes it as a unique 10-character alphanumeric identifier: two State-code digits, the letter D, and seven digits.
Does a passing result mean the laboratory is CLIA certified?
No. It means the text has the published layout. Check certification status with the CMS QCOR laboratory lookup or the State Agency.
Why must the third character be D?
In the CMS State Operations Manual the third position is an alpha character for the facility type, and D identifies CLIA laboratories.
Is a CLIA number the same as an NPI?
No. An NPI is a separate 10-digit provider identifier with a Luhn check digit; a CLIA number is the laboratory certification identifier.
Sources
- CMS, State Operations Manual, chapter 2 (Rev. 31) – supplier identification numbers (retrieved 2026-10)
- CMS, CLIA Certification Quick Start Guide, March 2026 (retrieved 2026-10)
- CMS CLIA program page and QCOR laboratory lookup (retrieved 2026-10)
Shape only
A correctly formatted value is not proof that an identifier was issued, is active or belongs to the person or business in front of you. Confirm with the issuing agency. This page is general information, not legal, tax or compliance advice.