On the Record · Quest Diagnostics

Quest Diagnostics subsidiaries, as it lists them

The subsidiaries Quest Diagnostics lists in its latest annual report, with the jurisdiction of each, linked to the filing.

Subsidiaries it lists

Subsidiary	Jurisdiction
Quest Diagnostics Holdings Incorporated	DE
Quest Diagnostics International Holdings Limited	UK
Quest Diagnostics Holdings Ltd.	UK
ExamOne Canada, Inc.	New Brunswick, Canada
Quest Diagnostics HTAS India Private Limited	India
Quest Diagnostics of Puerto Rico, Inc.	Puerto Rico
Quest Diagnostics Ireland Limited	Ireland
Quest Diagnostics (Shanghai) Co., Ltd.	China
Quest Diagnostics Clinical Laboratories, Inc.	DE
Quest Consumer Inc.	DE
Quest Procurement LLC	DE
Lab One , LLC	MO
Exam One World Wide, Inc.	PA
ExamOne LLC	DE
ExamOne World Wide of NJ, Inc.	NJ
DGXWMT JV, LLC	DE
PACK Health, LLC	AL
Quest HealthConnect, LLC	CA
Quest Diagnostics Health & Wellness, LLC	DE
Lab One of Ohio, Inc.	DE
Diagnostic Laboratory of Oklahoma LLC	OK
Sonora Quest Laboratories LLC	AZ
Quest Diagnostics do Brasil Ltda.	Brazil
Quest Diagnostics Incorporated	MD
Quest Diagnostics India Private Limited	India
Quest Diagnostics International LLC	DE
Quest Diagnostics Investments LLC	DE
Quest Diagnostics LLC	IL
Diagnostic Lab of Michigan, LLC	DE
Quest Diagnostics LLC	MA
Quest Diagnostics Massachusetts LLC	MA
Quest Diagnostics LLC	CT
Quest Diagnostics Mexico, S de RL de CV	Mexico
Quest Diagnostics Nichols Institute	CA
Quest Diagnostics of Pennsylvania Inc.	DE
Quest Diagnostics Venture LLC	PA
Associated Clinical Laboratories of Pennsylvania, L.L.C.	PA
Associated Clinical Laboratories, L.P.	PA
Quest Diagnostics Receivables Inc.	DE
Quest Diagnostics TB, LLC	DE
CML Healthcare Inc.	Ontario, Canada
LifeLabs GP ULC	Ontario, Canada
LifeLabs BC LP	Ontario, Canada
LifeLabs LP	Ontario, Canada
American Medical Laboratories, Incorporated	DE
Quest Diagnostics Nichols Institute, Inc.	VA
Quest Diagnostics Incorporated	NV
Blueprint Genetics Inc.	DE
Blueprint Genetics Oy	Finland
Blueprint Genetics FZ-LLC	UAE
Cleveland HeartLab, Inc.	DE
Haystack Oncology, Inc.	DE
Haystactack Oncology GmbH	Germany
Isabella Street Urban Renewal, LLC	NJ
Med Fusion, LLC	TX
Reprosource Fertility Diagnostics, Inc.	MA
Unilab Corporation	DE
AmeriPath, Inc.	DE
AmeriPath Cincinnati, Inc.	OH
AmeriPath Cleveland, Inc.	OH
AmeriPath Consolidated Labs, Inc.	FL
AmeriPath Florida, LLC	DE
AmeriPath Hospital Services Florida, LLC	DE
AmeriPath Kentucky, Inc.	KY
AmeriPath Lubbock 5.01(A) Corporation	TX
AmeriPath New York, LLC	DE
AmeriPath Texas Inc.	DE
AmeriPath Tucson, Inc.	AZ
Consolidated DermPath, Inc.	DE
DFW 5.01(a) Corporation	TX
Diagnostic Pathology Services, Inc.	OK
Kailash B. Sharma, M.D., Inc.	GA
Nuclear Medicine and Pathology Associates	GA
Institute for Dermatopathology, Inc.	PA
Ocmulgee Medical Pathology Association, Inc.	GA
Specialty Laboratories, Inc.	CA
AmeriPath Indianapolis, PC	IN
Colorado Pathology Consultants, P.C.	CO
Dermatopathology of Wisconsin, S.C.	WI
Hoffman, M.D., Associated Pathologists, Chartered	NV
Kilpatrick Pathology, P.A.	NC
PhenoPath Laboratories, PLLC	WA

From Exhibit 21 of the 10-K for 2025. Companies must list their significant subsidiaries there and may leave out smaller ones, so this is the company’s own list, not every entity it owns.

Read from Quest Diagnostics’s annual reports (10-K for 2025, 10-K for 2024, 10-K for 2023) and the financial data it files with the SEC, as of 2026-02-26. Every quotation is word for word from the filing linked beside it; how these pages are built and checked. The full record is in its company data sheet.