CLIA Compliance for Multiple Lab Locations
Under CLIA, each laboratory location normally needs its own certificate and CLIA number, so each site is surveyed, enrolled in proficiency testing and held to the rules on its own. Narrow exceptions cover mobile units, limited public health testing and contiguous hospital buildings. One person may direct no more than five laboratories.
Last reviewed Oct 2026 · By Sound Lab Consultants CLIA team · Based on the current text of 42 CFR Part 493. Not legal advice.
Key facts and official sources
Separate application for each location, with exceptions: 42 CFR 493.35 (waiver), §493.43 (registration/compliance), §493.55 (accreditation).
Five-laboratory limit for directors: §493.1407(d) (moderate complexity) and §493.1445(d) (high complexity).
Director on-site visits at least every 6 months, documented: §493.1407(c) and §493.1445(c).
Twice-a-year comparison of results across sites, instruments or methods: §493.1281.
No sending PT samples to another lab: §493.801(b)(5).
30-day change notification for Certificate of Compliance labs: §493.51.
Does each location need its own CLIA certificate?
Usually, yes. The certificate application rules say a laboratory must file a separate application for each laboratory location, except in three situations written into §493.35(b), §493.43(b) and §493.55(b):
Labs without a fixed location. Mobile units, health screening fairs and other temporary testing sites that move from site to site may be covered under the certificate of a designated primary site or home base, using its address.
Limited public health testing. Not-for-profit or federal, state or local government labs doing limited public health testing (no more than a combination of 15 moderately complex or waived tests per certificate) may file a single application.
Hospital labs on one campus. Labs within a hospital located in contiguous buildings on the same campus and under common direction may file a single application or multiple applications for sites within the same physical location or street address.
If your locations don't fit one of these exceptions, such as a group of clinics, urgent cares or freestanding ERs at different street addresses, plan on one CLIA certificate per site. Each site's certificate type must match the most complex testing done there, so one location can hold a Certificate of Waiver while another holds a Certificate of Compliance or Accreditation. Our CMS-116 application guide walks through the form for each new site.
How many locations can one lab director cover?
Both §493.1407(d) and §493.1445(d) say: "Each individual may direct no more than five laboratories." The limit is per person. A group with more than five certificated nonwaived sites needs more than one qualified director.
Since the personnel rule took effect on December 28, 2024, the director of a moderate or high complexity lab must also:
be on site at least once every 6 months, with at least 4 months between the two minimum visits;
document those visits, including evidence of the director duties performed; and
stay accessible to the lab for remote consultation as needed.
With five sites, that means planning and documenting at least ten on-site visits a year. Build them into a calendar and keep the visit records at each location, not only at headquarters. See CLIA lab director requirements for qualifications.
The director can delegate duties to qualified staff, such as a technical consultant at a moderate complexity site, but remains responsible for making sure every duty is done (§493.1407(a)–(b)).
What has to be done separately at every site?
Because each location is its own laboratory under CLIA, each one needs its own:
Proficiency testing enrollment for its regulated analytes. PT samples must be tested like patient specimens, and a lab must not send PT samples, or portions of them, to another lab for any analysis it is certified to perform itself (§493.801(b)(5)). Don't share PT samples between sister sites.
Quality control and maintenance records for the instruments actually used at that site.
Personnel files and competency assessments for the people who test there.
Procedure manual that matches the methods and instruments in use at that location.
Survey readiness. Each certificate is inspected on its own by the state agency or the lab's accreditor.
Where can a multi-site group standardize?
Shared systems make multiple locations easier to manage, as long as each site's records stay complete:
One SOP set for sites using the same instrument and method, with site-specific details (location, instrument serial numbers, contacts) added.
Same instruments and reagents across locations where practical, which simplifies training, QC ranges and verification.
Central review of QC, PT results and corrective actions by the director or technical consultant, with sign-offs recorded at each site.
Shared training and competency tools, with the six-element assessments performed and documented for each person at their site.
How do you compare results across locations?
Section 493.1281(a) requires a lab that performs the same test using different methods or instruments, or at multiple testing sites, to have a system that twice a year evaluates and defines the relationship between results. Define acceptance criteria in advance, document each comparison, and record what you did when results didn't agree (§493.1281(c)).
What changes must you report?
Labs with a Certificate of Compliance must notify HHS or its designee (in practice, the state agency) within 30 days of any change in ownership, name, location or director, and for high complexity labs, technical supervisor (§493.51(a)). New specialties and methodology changes have a 6-month notice window (§493.51(b)–(c)). Opening a new site, moving a site or changing a site's director usually means CMS-116 paperwork for that site. Other certificate types have parallel notification rules, so confirm with your state agency.
Common multi-site pitfalls
Opening a new location and starting testing before its own certificate is issued.
A director listed at more than five laboratories.
Director visits that happened but weren't documented at each site.
One PT enrollment or a shared PT sample covering several sites.
No twice-a-year comparison when sites run the same test on different instruments.
Copied procedure manuals that don't match the instrument a site actually uses.
Frequently asked questions
Can we use one CLIA number for all of our clinics?
Only if a regulatory exception applies, such as mobile testing under a home base, limited public health testing or contiguous hospital buildings on one campus. Otherwise, each location files its own application and receives its own CLIA number.
Can one lab director oversee several of our locations?
Yes, up to five laboratories per person under §493.1407(d) and §493.1445(d). For nonwaived labs, the director must also make documented on-site visits to each lab at least every 6 months.
Does a mobile testing unit need its own certificate?
Labs that move from site to site, such as mobile units or health fairs, may be covered under the certificate of a designated primary site or home base, using its address (§493.35(b)(1), §493.43(b)(1), §493.55(b)(1)).
Can two of our sites share proficiency testing?
No. Each certificated lab tests its own PT samples like patient specimens and must not send PT samples to another laboratory for analysis it is certified to perform (§493.801(b)(5)). Intentional referral can lead to revocation of the certificate for at least one year.
Do we have to compare results between locations?
Yes, if you perform the same test at multiple testing sites or on different instruments or methods. Section 493.1281 requires a system that evaluates the relationship between results twice a year, with documentation.
Check every site before the surveyor does
Not sure each location is set up correctly? Start with our free CLIA readiness check, then talk with us about oversight across your sites. Sound Lab Consultants works with multi-location groups nationwide. Pricing starts at $500 and increases with lab complexity and the number of instruments.