Form 8-K
8-K — QUEST DIAGNOSTICS INC
Accession: 0000947871-26-000941
Filed: 2026-10-22
Period: 2026-10-21
CIK: 0001022079
SIC: 8071 (SERVICES-MEDICAL LABORATORIES)
Item: Other Events
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8-K — ss6979200_8k.htm (Primary)
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8-K — CURRENT REPORT
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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, DC 20549
FORM 8-K
CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF
THE SECURITIES EXCHANGE ACT OF 1934
Date of Report (Date of Earliest Event
Reported): October 21, 2026
Quest Diagnostics Incorporated
(Exact Name of Registrant as Specified in Its
Charter)
Delaware
(State or other jurisdiction of incorporation)
001-12215
16-1387862
(Commission File Number)
(I.R.S. Employer Identification No.)
500 Plaza Drive
Secaucus, NJ
07094
(Address of principal executive offices)
(Zip Code)
(973) 520-2700
(Registrant's telephone number, including area code)
Check the appropriate box below if the Form 8-K filing is intended
to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2.
below):
o Written communications pursuant
to Rule 425 under the Securities Act (17 CFR 230.425)
o Soliciting material pursuant
to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
o Pre-commencement communications
pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
o Pre-commencement communications
pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
Securities registered pursuant to Section 12(b) of the Act:
Title of each class
Trading Symbol(s)
Name of each exchange on which registered
Common Stock, $0.01 Par Value
DGX
New York Stock Exchange
Indicate by check mark whether the registrant is an emerging growth company
as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934
(§240.12b-2 of this chapter).
Emerging growth company o
If an emerging growth company, indicate by check mark if the registrant
has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant
to Section 13(a) of the Exchange Act. o
Item 8.01. Other Events.
On October 21, 2026, Quest Diagnostics Incorporated
(the “Company”) learned of unauthorized access to its Quanum LSM system, which certain clients use to place test orders,
receive and look up results. The Company promptly initiated its cybersecurity incident response procedures to contain the activity, assess
and investigate the nature and scope of the incident and implement appropriate remedial measures. The Company has notified federal law
enforcement authorities and engaged external cybersecurity experts to assist in the investigation and response. While the full scope
of unauthorized access remains under investigation, at this time the Company believes that an unauthorized party accessed certain patient
records. This incident has not materially disrupted the Company’s business operations or its ability to serve patients.
The statements in this report which are not historical facts may be forward-looking
statements. Readers are cautioned not to place undue reliance on forward-looking statements, which speak only as of the date that they
are made and which reflect management’s current estimates, projections, expectations or beliefs and which involve risks and uncertainties
that could cause actual results and outcomes to be materially different. Risks and uncertainties that may affect the future results of
the company include, but are not limited to, the impact of the incident described in this report, uncertain and volatile economic conditions,
adverse results from pending or future government investigations, lawsuits or private actions, the competitive environment, the complexity
of billing, reimbursement and revenue recognition for clinical laboratory testing, changes in government policies, including related
to trade, and regulations, changing relationships with customers, payers, suppliers or strategic partners, acquisitions and other factors
discussed in the company's most recently filed Annual Report on Form 10-K and in any of the company’s subsequently filed Quarterly
Reports on Form 10-Q and Current Reports on Form 8-K, including those discussed in the “Business,” “Risk Factors,”
“Cautionary Factors that May Affect Future Results” and “Management’s Discussion and Analysis of Financial Condition
and Results of Operations” sections of those reports.
Signature
Pursuant to the requirements of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized.
October 22, 2026
QUEST DIAGNOSTICS INCORPORATED
By:
/s/ Sean D. Mersten
Sean D. Mersten
Vice President and Corporate Secretary
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Entity Central Index Key
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Entity Tax Identification Number
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Entity Incorporation, State or Country Code
DE
Entity Address, Address Line One
500 Plaza Drive
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