I've heard for a number of years that CAP allows "distributive testing" of parts of one complex test when two labs formally collaborate.
- For example, a CLIA lab in Chicago might do sequencing and a CLIA lab in St Louis might do bioinformatics. (They are mutually responsible for quality assurance, etc.)
I've also heard, informally, that distributive testing might raise eyebrows with the AMA PLA code committee. I've never seen that myself.
I asked Chat GPT 5 to research this and get back to me. Note, I am not an expert in this area, so I would use this information below only as a launch pad for my own research, I'd need to check the links carefully, etc. Note that the results include a website that uses the term "dry lab" to refer to a bioinformatics lab.
Quiz:
- Would I take the AI essay below as fact, like a textbook?
- NO!
- Would the organized and hotlinked info below speed me up to use this and its links as a starting point?
- Yes.
###
Prompt. Please do internet research on this arcane topic . The College of American Pathologists has some formal principal in its review of laboratories (a CLIA function) that a test may be distributed in two laboratories under a formal collaboration if each has a clia license. For example sequencing in CLIA LAB A in chicacgo and by arrangement bioinformatics in CLIA LAB B in St Louis. This has a name like "distributing testing' at CAP. The real term may differ (which is my issue). Please find information about this as I need to document it for a client. Use the internet.
## Chat GPT 5 writes,
Short version: the term you’re looking for is “distributive testing” under CLIA, and CAP generally refers to a “distributive testing model” or “CAP Distributive Model” for things like splitting wet-lab NGS in one CLIA lab and bioinformatics / interpretation in another.
Below is the information I found, with citations.
1. Regulatory term under CLIA: “distributive testing”
CMS now explicitly defines distributive testing in its CLIA guidance. In a 2024 CMS brochure on Proficiency Testing and PT Referral, CMS explains that laboratories may send patient specimens for additional testing (distributive, confirmatory, reflex) while PT samples must not be sent out. The brochure describes distributive testing as the situation where a specimen would ordinarily be forwarded to another lab for additional testing to complete an interpretation or calculation for the final report. (Centers for Medicare & Medicaid Services)
A more precise definition appears in a 2024 CLIA policy memo (QSO-25-10-CLIA) and in CMS educational materials: distributive testing is laboratory testing performed on the same specimen (or an aliquot) that requires sharing it between two or more laboratories, each under different CLIA certificates, to obtain all data required to issue the final reportable result. (Centers for Medicare & Medicaid Services)
https://www.cms.gov/regulations-and-guidance/legislation/clia/downloads/cliabrochure8.pdf
CLIAC’s 2019 recommendations on non-traditional workflow models explicitly refer to a “distributive testing” carve-out in CLIA PT rules at 42 CFR 493.801(b)(4), recognizing that CLIA must be able to evaluate quality across the whole testing cycle when testing is split across labs. (Restored CDC)
So at the federal regulatory level, the operative term really is “distributive testing” (and “distributive testing models”).
2. CAP’s terminology: “distributive testing model” / “CAP Distributive Model”
CAP advocacy and CLIA oversight
In an April 19, 2022 advocacy update, CAP told CLIAC that “all aspects of clinical laboratory testing performed in a distributive testing model should be regulated under CLIA, including bioinformatics and cloud-based software computing.” (College of American Pathologists)
https://www.cap.org/advocacy/latest-news-and-practice-data/april-19-2022#story1
Regardless of where any of the test components are performed, laboratories should observe good laboratory practices throughout the total testing process....Nontraditional sites that are increasing include distributive testing sites. The CAP asserted that all aspects of clinical laboratory testing performed in a distributive testing model should be regulated under CLIA, including bioinformatics and cloud-based software computing. The CAP further urged CLIAC to recognize bioinformatics facilities (including stand-alone facilities) as subject to CLIA, add personnel requirements for bioinformaticists, and revamp proficiency testing (PT) requirements to test the total testing process.
CAP urged CMS/CLIAC to:
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Recognize bioinformatics facilities, including stand-alone facilities, as laboratories subject to CLIA.
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Add personnel requirements for bioinformaticists.
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Update PT requirements to test the total testing process in distributive models. (College of American Pathologists)
That is exactly your Chicago CLIA lab A (sequencing) + St. Louis CLIA lab B (bioinformatics) scenario: CAP is explicitly saying that both components of the test in this distributive testing model must fall under CLIA and be inspected/accredited.
CAP proficiency-testing guidance
In its 2025 Molecular PT Recommendations document, CAP repeatedly refers to a “distributive testing model” in the context of NGS PT enrollment. The flow charts tell labs what PT programs they must enroll in “if a distributive testing model is used” (e.g., NGS bioinformatics performed at a separate site), and point to a separate NGS Bioinformatics Flow Chart for such situations. (CAP Documents)
Again, this treats the wet-lab and the bioinformatics site as part of one end-to-end test that must be covered by appropriate CAP-recognized PT across all participating locations.
CAP-based secondary guidance (NGS & bioinformatics)
Several peer-reviewed papers and CAP-linked resources describe CAP’s expectations for distributive models:
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A 2024 article in Archives of Pathology & Laboratory Medicine notes that some laboratories use a distributive testing model for NGS where the bioinformatics component is performed by a separate entity. (Meridian)
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An ACMG technical standard for NGS (Rehder et al.) cites CAP guidance that any test using a distributive model requires an integrated validation that includes both wet bench and bioinformatics components. (ScienceDirect)
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A 2025 Journal of Molecular Diagnostics paper on clinical bioinformaticians mentions a “distributive testing model where the wet laboratory component is run in a CLIA-licensed laboratory and the bioinformatics pipeline is run by another”, again mirroring your example. (JMD Journal)
All of these reinforce that CAP’s framework for splitting NGS across labs is routinely referred to as a “distributive testing model.”
3. “CAP Distributive Model” – practical description
While the formal checklists are behind the CAP login, vendors and CAP-accredited labs have published clear descriptions of how they implement what they call the CAP Distributive Model:
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PierianDx’s “CAP Distributive Model of NGS Testing” blog defines three phases of an NGS test:
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Wet lab – accessioning, nucleic-acid evaluation, library prep, sequencing
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Dry lab – variant calling, annotation, classification, data visualization, QC
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Professional phase – clinical interpretation, reporting, MD sign-out (Pierian)
Pierian states (summarizing CAP’s model) that any CLIA-certified or CAP-accredited lab may outsource any of these three components (wet, dry, or professional) to another CLIA-certified or CAP-accredited lab, to build a distributive NGS program. (Pierian)
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A detailed PierianDx webinar transcript on the CAP Distributive Model shows practical implementations where:
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A referral CLIA lab performs sample receipt and wet-lab steps, and perhaps initial base-calling.
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FastQ files are pushed to another CLIA-licensed lab for variant calling and annotation.
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The final professional interpretation and report sign-out is performed under a designated CLIA lab (which might be yet another site). (Pierian)
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These examples are directly aligned with the Chicago-wet-lab / St-Louis-bioinformatics pattern you described, and are explicitly described as CAP-compatible implementations.
4. How to describe this to a client
Here is a concise, documentation-ready paragraph you can adapt:
Under CLIA, “distributive testing” refers to testing on a single specimen (or aliquots) that is shared between two or more laboratories, each operating under its own CLIA certificate, in order to obtain all data required for a single final reportable result (see CMS PT and CLIA guidance and the PT carve-out at 42 CFR 493.801(b)(4)). (Centers for Medicare & Medicaid Services) The College of American Pathologists has operationalized this concept as a “distributive testing model” or “CAP Distributive Model,” in which different components of a clinical test (for example, NGS wet-lab sequencing, bioinformatics analysis, and professional interpretation and report sign-out) may be performed at separate CLIA-certified / CAP-accredited laboratories under formal collaboration. CAP has advised CLIAC that all aspects of testing in such a distributive testing model – including bioinformatics and cloud-based software computing – should be regulated under CLIA, and CAP’s own PT and NGS guidance require an integrated, end-to-end validation and appropriate proficiency-testing coverage across all participating sites. (College of American Pathologists)
If you want to be more concrete for NGS:
For NGS assays, CAP and derivative guidance typically divide the workflow into wet-lab, dry-lab (bioinformatics), and professional components. Under the CAP Distributive Model, a CLIA-accredited laboratory may perform, for example, wet-lab and primary sequencing in Lab A (Chicago), transfer sequence data (e.g., FastQ files) to Lab B (St. Louis) for bioinformatics analysis, and have the final professional interpretation and sign-out in either Lab A or Lab B – provided that (i) each site holds an appropriate CLIA certificate (and CAP accreditation, if using CAP as the accrediting organization), (ii) there is an integrated validation of the end-to-end workflow, and (iii) proficiency-testing and quality-management programs encompass all parts of the distributed process. (Pierian)
5. Key phrases you can safely use
For your written materials, you can confidently use:
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“Distributive testing” – CLIA term (CMS and CLIAC documents). (Centers for Medicare & Medicaid Services)
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“Distributive testing model” – used by CAP in advocacy and PT/NGS documents. (College of American Pathologists)
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“CAP Distributive Model” – widely used in CAP-aligned NGS implementation discussions (e.g., PierianDx materials describing CAP-compliant outsourcing of wet, dry, and professional phases between CLIA/CAP labs). (Pierian)
If you’d like, I can next draft a one-page client-facing explainer with a diagram of wet-lab vs dry-lab vs professional components under a CAP Distributive Model.
