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.

LOINCActiveObservation

LOINC Code 90801-2: TSH 6 Hr post dose levothyroxine Qn

Name: LOINC Code 90801-2: TSH 6 Hr post dose levothyroxine Qn
Creator: HealthAssure Clinical Team
Published: 2026-05-21T09:00:20.875Z

90801-2 is a LOINC code used to identify TSH 6 Hr post dose levothyroxine Qn 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 Thyrotropin^6H post dose levothyroxine. It is commonly used with the system or sample type Ser/Plas.

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 Thyrotropin^6H post dose levothyroxine. It is commonly used with the system or sample type Ser/Plas.

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: Observation

What it does not mean

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

Key facts

Thyrotropin [Units/volume] in Serum or Plasma --6 hours post dose levothyroxine
Thyrotropin^6H post dose levothyroxine
>6h; 6h p levo; After; Arbitrary concentration; c99; CHEMISTRY.CHALLENGE TESTING; Endocrine; Endocrinology; L-thyroxine; p dose; Pl; Plasma; Plsm; Point in time; PST; QNT; Quan; Quant; Quantitative; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; SR; Thyroid stimulating hormone; Thyrotropic hormone; TSH

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

TSH 6 Hr post dose levothyroxine QnThyrotropin [Units/volume] in Serum or Plasma --6 hours post dose levothyroxineTSH 6h p levo SerPl-aCncThyrotropin^6H post dose levothyroxineCHALThyroid Stimulating Hormone (TSH; Thyrotropin) 6 hr after levothyroxine, BloodACnc

Frequently asked questions

Code details

Code90801-2

SystemLOINC

Display nameTSH 6 Hr post dose levothyroxine Qn

DescriptionThyrotropin^6H post dose levothyroxine

Short nameTSH 6h p levo SerPl-aCnc

ComponentThyrotropin^6H post dose levothyroxine

PropertyACnc

TimingPt

System (specimen)Ser/Plas

ScaleQn

ClassCHAL

Example unitsmIU/mL

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.65

Last changed2.65

Consumer names

Thyroid Stimulating Hormone (TSH; Thyrotropin) 6 hr after levothyroxine, Blood

Part names

Thyrotropin^6H post dose levothyroxineACncPtSer/PlasQnArbitrary ConcentrationPoint in time (spot)Serum or Plasma

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.