LOINCBoth

LOINC Code 3023-9: T4 uptake [Mass/Vol]

3023-9 is a LOINC code used to identify T4 uptake [Mass/Vol] 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 Thyroxine uptake. 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 Thyroxine uptake. 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: DEPRECATED
  • Order vs observation: Both

What it does not mean

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

Key facts

  • Deprecated Thyroxine (T4) uptake [Mass/volume] in Serum or Plasma
  • Thyroxine uptake
  • Chemistry; Level; Levothyroxine; Levo-thyroxine; L-thyroxine; Mass concentration; Pl; Plasma; Plsm; Point in time; QNT; Quan; Quant; Quantitative; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; SR; T4; T-4; T4U; thyroid hormone; Thyrox; Thyroxin; Thyrx; Total T4; TT4

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

T4 uptake [Mass/Vol]Deprecated Thyroxine (T4) uptake [Mass/volume] in Serum or PlasmaDeprecated T4U SerPl-mCncThyroxine uptakeCHEMT4 uptake, BloodMCnc

Frequently asked questions

Code details

Code3023-9
SystemLOINC
Display nameT4 uptake [Mass/Vol]
DescriptionThyroxine uptake
Short nameDeprecated T4U SerPl-mCnc
ComponentThyroxine uptake
PropertyMCnc
TimingPt
System (specimen)Ser/Plas
ScaleQn
ClassCHEM
StatusDEPRECATED
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0
Last changed2.48

Consumer names

T4 uptake, Blood

Part names

Thyroxine uptakeMCncPtSer/PlasQnMass 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.

LOINC Code 3023-9 | HealthAssure