Labcorp Explained – Services, Testing, and Drug Screening Explained

Laboratory Corporation of America, operating publicly as Labcorp (NYSE: LH), is one of the largest clinical laboratory networks in the world. Headquartered in Burlington, North Carolina, the company processes an enormous volume of diagnostic work—more than 700 million tests annually—for patients, physicians, hospitals, employers, and pharmaceutical researchers across approximately 100 countries. With nearly 70,000 employees and 2024 revenues of $13.01 billion, Labcorp operates at a scale that makes it a foundational part of healthcare infrastructure in the United States and beyond.

This article provides an overview of what Labcorp does, the types of laboratory services it offers, and a detailed look at one of its major service areas: workplace and clinical drug testing.

Company Background

Labcorp traces its roots to the 1995 merger of National Health Laboratories and Roche Biomedical Laboratories, two large independent laboratory operations. In 2023, the company completed the spinoff of its drug development segment, which became a separate public company called Fortrea Holdings. This allowed Labcorp to sharpen its focus on its core diagnostics business.

The company reorganized again in May 2024, forming Labcorp Holdings Inc. as a new public holding company while retaining Laboratory Corporation of America Holdings as the operating subsidiary. Today, Labcorp is organized into two business segments:

What Labcorp Tests For: Core Diagnostic Services

Labcorp’s diagnostic menu covers a wide spectrum of clinical needs, from routine blood panels ordered during annual physicals to highly specialized genetic and molecular testing. The company operates more than 2,000 patient service centers across the U.S., as well as 14 primary testing sites and 16 specialty testing sites.

Routine testing includes commonly ordered tests such as:

Specialty and esoteric testing covers more complex diagnostic areas, including:

Labcorp also provides occupational testing services—a category that includes its extensive workplace drug and alcohol testing programs.

Drug Testing at Labcorp: An Overview

Drug testing is a significant part of Labcorp’s Diagnostics segment. The company has more than 30 years of experience providing substance abuse testing services to employers, federal agencies, clinical providers, and individuals. Its workplace testing laboratories are certified by two key bodies:

Notably, Labcorp was the first SAMHSA-certified laboratory system to introduce a fully digital chain of custody form, simplifying documentation across the collection-to-result process.

Drug testing at Labcorp serves multiple purposes, including pre-employment screening, random workplace testing, post-accident investigation, and clinical monitoring (such as pain management or substance use treatment programs).

Types of Drug Tests Available

Labcorp offers several specimen types for drug testing. Each has different practical applications, detection windows, and collection requirements.

Urine Drug Testing

Urine testing is the most widely used method. It is cost-effective, non-invasive, and capable of detecting a broad range of substances. Standard panels typically range from five to ten drug classes. Urine is the only specimen type accepted for federally mandated testing under Department of Transportation (DOT) regulations.

Labcorp offers both laboratory-based urine testing and rapid point-of-collection testing (POCT) for urine. In POCT, an initial screen is performed on-site using an immunoassay device, with non-negative results sent to the lab for confirmation.

Oral Fluid (Saliva) Drug Testing

Oral fluid testing collects saliva using a specialized device and has gained traction in recent years. The Department of Health and Human Services (HHS) approved oral fluid as a matrix for federal workplace drug testing programs, making it a growing alternative to urine for some employers.

Oral fluid is particularly effective for detecting recent drug use and is well-suited to post-accident and reasonable-suspicion scenarios. Collection is observed by default, which reduces the risk of specimen tampering. Donors must refrain from eating or drinking for 10 minutes before the swab is taken.

Hair Drug Testing

Hair testing analyzes a small sample of hair—typically 1.5 inches taken from close to the scalp—to detect drug use over a longer historical window. Because drugs and their metabolites are incorporated into the hair shaft from the bloodstream as hair grows, a 1.5-inch sample generally reflects approximately 90 days of potential drug exposure. A standard hair drug test with initial screen and confirmation requires about 100 milligrams of hair, or 90 to 120 strands.

Hair testing is not accepted for federally mandated DOT testing but is widely used in non-DOT employer programs, particularly when historical drug use history is more relevant than recent use.

Blood Drug Testing

Blood testing detects active drug presence rather than metabolites that linger after the drug has been processed. Because drugs are metabolized and cleared from the bloodstream quickly, blood testing is most appropriate when there is reason to suspect someone is currently impaired, such as immediately following a workplace accident. It is the least commonly used method for routine screening due to its invasive nature and short detection window.

Drug Panels: Substances and Metabolites Tested

Rather than testing for drugs themselves, most drug tests detect metabolites—the chemical byproducts the body produces as it processes a substance. Labcorp offers configurable panels, from the federally standardized five-panel to expanded ten-panel options and beyond.

The Standard 5-Panel (DOT)

Required for federally regulated industries under DOT, this panel covers:

Drug Class Primary Metabolite(s) Detected
Marijuana (cannabis) THC-COOH (tetrahydrocannabinol carboxylic acid)
Cocaine Benzoylecgonine
Opiates Codeine, morphine, hydrocodone, hydromorphone
Amphetamines Amphetamine, methamphetamine
Phencyclidine (PCP) PCP

The 10-Panel (Non-DOT)

Non-DOT employers who want broader coverage commonly use a 10-panel test, which adds five additional drug classes to the standard five:

Additional Drug Class Notes
Benzodiazepines Includes metabolites such as nordiazepam, oxazepam, lorazepam, and others; expanded confirmation available
Barbiturates Sedative/hypnotic drugs
Methadone Synthetic opioid used medically; can indicate illicit use
Propoxyphene A pain-reliever class
Oxycodone/Oxymorphone Common prescription opioids often added as a separate screen

For opiates, positive screens can be confirmed to identify specific compounds including codeine, hydrocodone, hydromorphone, and morphine. Labcorp also notes that 6-acetylmorphine (6-AM)—an intermediate metabolite specific to heroin metabolism—can be identified in urine or oral fluid, since it is only present following heroin use rather than other opioids.

Expanded and Custom Panels

Labcorp offers expanded benzodiazepine confirmation panels, fentanyl and synthetic opioid add-ons, MDMA/ecstasy screening, and other customizable options to reflect evolving drug use trends. Employers outside federal regulation can configure panels to address the specific risk profile of their industry or workforce.

Detection Windows by Specimen Type

Detection windows are not fixed values. They depend on the substance itself, the dose and frequency of use, the individual’s metabolism, and the concentration thresholds set by the testing program. The table below represents general ranges commonly cited across Labcorp’s documentation and industry guidelines.

Specimen Typical Detection Window
Oral fluid (saliva) 5–48 hours after last use
Blood Hours (varies significantly by drug)
Urine 1–7 days (longer for chronic or heavy users)
Hair Up to approximately 90 days

How the Drug Testing Process Works

Regardless of which specimen type or panel is used, laboratory-based drug testing at Labcorp follows a structured, documented process designed to produce legally defensible results.

  1. Test Authorization: An employer, healthcare provider, or individual orders a test. For workplace programs, the donor is directed to a Labcorp patient service center or authorized collection site.
  2. Specimen Collection: The collector verifies the donor’s identity, explains the process, and collects the specimen. A Custody and Control Form (CCF) is completed at the time of collection, documenting the chain of custody from that point forward. Both the donor and collector sign the form, and the specimen is sealed with tamper-evident labels in the donor’s presence.
  3. Laboratory Screening: The sealed specimen is shipped to a Labcorp SAMHSA-certified facility. An initial screen using immunoassay technology is performed. The large majority of specimens screen negative and are reported promptly.
  4. Confirmation Testing: Any specimen that screens non-negative (presumptively positive) proceeds to confirmatory testing using gas chromatography/mass spectrometry (GC/MS) or liquid chromatography with tandem mass spectrometry (LC/MS/MS). These techniques identify specific molecules and their concentrations, providing a high level of analytical certainty. A result is only reported as positive if the confirmed concentration meets or exceeds the applicable cutoff threshold.
  5. Medical Review Officer (MRO) Review: In regulated workplace programs, all non-negative results are reviewed by a Medical Review Officer—a licensed physician trained in substance abuse and drug testing. The MRO contacts the donor to discuss whether any prescription medication or other legitimate medical explanation accounts for the result before reporting a final outcome to the employer.
  6. Results Reporting: Final results are communicated to the employer or requesting party. Labcorp provides web-based tools for employers to access results, view chain-of-custody documentation, and manage their testing programs electronically.

When Drug Testing Is Conducted

Labcorp’s drug testing services support several distinct testing scenarios:

Summary

Labcorp is a large-scale diagnostics company offering an extensive range of laboratory services—from routine bloodwork to advanced genetic and molecular testing. Its drug testing division is one of the most established in the U.S., operating certified laboratories and collection sites that serve employers, clinical providers, and federal programs alike.

Drug testing at Labcorp covers multiple specimen types (urine, oral fluid, hair, and blood), configurable panels ranging from five to ten or more drug classes, and a well-documented process that includes immunoassay screening, mass spectrometry confirmation, and MRO review. Detection windows, substances tested, and appropriate test type all vary depending on the specific program and its requirements—factors that employers and individuals should discuss with a testing coordinator or occupational health provider when designing or participating in a drug testing program.