Quest Diagnostics Incorporated (DGX)
Quest Diagnostics runs a national network of clinical laboratories providing medical testing.
DGX vs LH: how the two businesses compare
- Bigger business: LH, with $14.0B of yearly revenue, about 1.3× DGX's $11.0B.
- More profitable: DGX keeps 9 cents of each sales dollar as profit, against 6 cents at LH.
- More cash from each sale: DGX turns 17 cents of each sales dollar into operating cash flow, against 12 cents at LH.
From each company's latest annual SEC filing. Fiscal years can end on different dates.
Laboratory Corporation of America (LH) is the larger business by reported revenue: $14.0B in its fiscal year ended Dec 2025, about 1.3× DGX's $11.0B (fiscal year ended Dec 2025). DGX's net margin was 9.0% and LH's 6.3%. Both file with the SEC under the same industry code, SIC 8071 (Services-Medical Laboratories).
Figures come from each company's own SEC filings. This page compares the businesses; it is not a price target or a verdict.
- Health Care
- Medical Laboratories
- Same classification
- December 31
- Same calendar
- Feb 26, 2026
DGX vs LH: quick comparison
| Company fact | DGX | LH |
|---|---|---|
| Company | Quest Diagnostics Incorporated | Laboratory Corporation of America Holdings |
| Exchange | NYSE | NYSE |
| SEC industry | Services-Medical Laboratories | Services-Medical Laboratories |
| Fiscal year-end | December 31 | December 31 |
| Latest annual filing | 10-K · 2026-02-26 | 10-K · 2026-02-24 |
DGX vs LH: audited financials
- Scale: LH's $14.0B of revenue is about 1.3× DGX's $11.0B.
- Net margin: DGX kept 9.0% of revenue as net income versus 6.3% at LH.
- Cash conversion: operating cash flow equalled DGX 17.1% of revenue, or 1.90× net income; LH 11.8% of revenue, or 1.87× net income. A ratio well above 1× usually reflects non-cash charges or working-capital release; well below 1× can reflect working-capital build or non-cash gains.
- Periods: both fiscal years end on 2025-12-31, so these annual figures cover the same months.
| Metric | DGX | LH |
|---|---|---|
| Revenue | $11.0B2025-01-01 to 2025-12-31 · SEC filing | $14.0B2025-01-01 to 2025-12-31 · SEC filing |
| Net income | $992M2025-01-01 to 2025-12-31 · SEC filing | $877M2025-01-01 to 2025-12-31 · SEC filing |
| Operating cash flow | $1.9B2025-01-01 to 2025-12-31 · SEC filing | $1.6B2025-01-01 to 2025-12-31 · SEC filing |
| Diluted EPS | $8.752025-01-01 to 2025-12-31 · SEC filing | $10.462025-01-01 to 2025-12-31 · SEC filing |
| Net margin | 9.0%2025-01-01 to 2025-12-31 · SEC filing | 6.3%2025-01-01 to 2025-12-31 · SEC filing |
DGX: FY ending 2025-12-31 · LH: FY ending 2025-12-31. Figures as tagged in each issuer's SEC XBRL filing; fiscal calendars may not align.
Where DGX and LH overlap, and where they don't
Overlap
- Same SEC industry: both report under SIC 8071, Services-Medical Laboratories.
- Same fiscal calendar: both fiscal years end December 31.
Differences
No differences in classification, themes, or calendar are recorded in the data; the differences sit in the businesses described below.
Overlap is drawn from SEC classifications and Yield Theory research themes. It is not evidence that the companies sell to the same customers or compete product for product.
Laboratory Corporation of America Holdings (LH)
Labcorp operates clinical laboratories providing diagnostic testing and drug-development services.
What moves each company
Company-specific drivers maintained by Yield Theory. Use them to decide which filing deserves deeper work; they are not predictions.
What moves DGX
We have not yet published a company-specific driver list for DGX. The primary source is Item 1 (Business) and Item 1A (Risk Factors) of its 10-K filed 2026-02-26.
What moves LH
We have not yet published a company-specific driver list for LH. The primary source is Item 1 (Business) and Item 1A (Risk Factors) of its 10-K filed 2026-02-24.
The investment question
You now know LH reports about 1.3× DGX's revenue, and DGX keeps more of each dollar as net income. Those are the facts. The investment question is what each share price already assumes about the services-medical laboratories cycle, and which evidence in the next filings would prove that assumption wrong.
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Read the full researchSEC filing comparison and disclosure evidence
Start with primary filings because fiscal calendars and accounting presentation can make superficially similar quarters incomparable. Both fiscal years end December 31, so annual reports line up, but check segment definitions before comparing growth or margins.
The current verified House and Senate snapshot contains 9 matched transaction rows for DGX and 20 matched transaction rows for LH. These delayed, range-based disclosures can identify a filing to inspect; they do not establish motive, conviction, or a real-time trading signal.
DGX primary filings
LH primary filings
What this comparison cannot tell you
This page does not contain licensed live prices, a valuation model, earnings estimates, portfolio constraints, or a forecast of future returns. SEC classifications can be broad, company descriptions can lag strategic change, and the latest annual filing may predate a material acquisition or divestiture. Read subsequent quarterly and current reports before making a decision.
A stronger business is not automatically the better stock. Starting valuation, expectations, capital structure, cyclicality, dilution, and the probability of each thesis determine the investment outcome. Use this comparison to frame the work, then verify the numbers in the linked filings and current company disclosures.
DGX vs LH FAQs
Are DGX and LH direct competitors?
Quest Diagnostics and Laboratory Corporation of America share the SEC industry classification “Services-Medical Laboratories.” That makes the operating comparison relevant, but it does not prove that every product, customer, or revenue stream competes directly.
Is DGX or LH the bigger company by revenue?
Laboratory Corporation of America (LH) is the larger business by reported revenue: $14.0B in its fiscal year ended Dec 2025, about 1.3× DGX's $11.0B (fiscal year ended Dec 2025). DGX's net margin was 9.0% and LH's 6.3%. Both file with the SEC under the same industry code, SIC 8071 (Services-Medical Laboratories). Each figure is the annual amount tagged in the company's own SEC XBRL filing; market value depends on live prices, which this page does not publish.
Which is better, DGX or LH?
There is no context-free winner. Compare the operating exposures, filing evidence, valuation, balance sheet, and risks against the specific thesis you are testing. This page deliberately does not turn a static profile into a buy or sell recommendation.
Does this DGX vs LH comparison include live prices?
No. Yield Theory does not republish unlicensed real-time market data. The financial figures on this page are the audited annual numbers Quest Diagnostics Incorporated and Laboratory Corporation of America Holdings tagged in their SEC XBRL filings. Use a regulated broker or licensed quote provider for current prices and valuation multiples.
Where does the company information come from?
Company classifications, fiscal year-ends, and filing links come from the SEC EDGAR submissions API snapshot refreshed 2026-11-09. Business summaries and research themes are maintained by Yield Theory.
Data snapshot: SEC EDGAR submissions API, refreshed 2026-11-09. Independent educational research; not investment advice.
Which business differences matter to the investment thesis?
DGX vs LH compares reported results. The reports below show how we connect operating evidence to an investment thesis, its assumptions, catalysts, and risks. $39/month or $249/year.
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