What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveBoth

LOINC Code 21556-6: Tetrahydrocannabinol Screen method >20 ng/mL Ql (U)

Name: LOINC Code 21556-6: Tetrahydrocannabinol Screen method >20 ng/mL Ql (U)
Creator: HealthAssure Clinical Team
Published: 2026-05-21T11:17:29.463Z

21556-6 is a LOINC code used to identify Tetrahydrocannabinol Screen method >20 ng/mL Ql (U) in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Tetrahydrocannabinol. It is commonly used with the system or sample type Urine.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Tetrahydrocannabinol. It is commonly used with the system or sample type Urine.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: ACTIVE
Order vs observation: Both
Method: Screen>20 ng/mL

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Tetrahydrocannabinol [Presence] in Urine by Screen method >20 ng/mL
Tetrahydrocannabinol
Delta(9)-THC; Delta-9-tetrahydrocannabinol; Dronabinol; DRUG/TOXICOLOGY; Drugs; Marijuana; Nabilone; Nasogastric; Ordinal; Point in time; PR; QL; Qual; Qualitative; Random; Scn; Scn>20 ng/mL; Scr; Screen; Scrn; THC; UA; UR; Urn

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Tetrahydrocannabinol Screen method >20 ng/mL Ql (U)Tetrahydrocannabinol [Presence] in Urine by Screen method >20 ng/mLTHC Ur Ql Scn>20 ng/mLTetrahydrocannabinolDRUG/TOXTetrahydrocannabinol, UrinePrThr

Frequently asked questions

Code details

Code21556-6

SystemLOINC

Display nameTetrahydrocannabinol Screen method >20 ng/mL Ql (U)

DescriptionTetrahydrocannabinol

Short nameTHC Ur Ql Scn>20 ng/mL

ComponentTetrahydrocannabinol

PropertyPrThr

TimingPt

System (specimen)Urine

ScaleOrd

MethodScreen>20 ng/mL

ClassDRUG/TOX

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0m

Last changed2.73

Consumer names

Tetrahydrocannabinol, Urine

Part names

TetrahydrocannabinolPrThrPtUrineOrdScreen>20 ng/mLPresence or ThresholdPoint in time (spot)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.