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.

LOINCBoth

LOINC Code 3022-1: Free T4 index [Mass/Vol]

Name: LOINC Code 3022-1: Free T4 index [Mass/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:16.074Z

3022-1 is a LOINC code used to identify Free T4 index [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 free index. 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 free index. 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 free index in Serum or Plasma
Thyroxine free index
This index is used to correct the estimated total thyroxine for the amount of thyroxine binding globulin present. It uses the THYROXINE (T4) and the TRIIODOTHYRONINE (T3) UPTAKE INDEX values.
Chemistry; FR; FreeT4; FT4; FT4I; FTI; Level; Levothyroxine; Levo-thyroxine; L-thyroxine; Mass concentration; Non-protein bound; Pl; Plasma; Plsm; Point in time; QNT; Quan; Quant; Quantitative; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; SR; T4; T-4; T4 Free; T7; 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

Free T4 index [Mass/Vol]Deprecated Thyroxine free index in Serum or PlasmaDeprecated FTI SerPl-mCncThyroxine free indexCHEMFree T4 Index, BloodMCnc

Frequently asked questions

Code details

Code3022-1

SystemLOINC

Display nameFree T4 index [Mass/Vol]

DescriptionThyroxine free index

Short nameDeprecated FTI SerPl-mCnc

ComponentThyroxine free index

PropertyMCnc

TimingPt

System (specimen)Ser/Plas

ScaleQn

ClassCHEM

Example unitsug/dL

StatusDEPRECATED

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0

Last changed2.40

Consumer names

Free T4 Index, Blood

Part names

Thyroxine free indexMCncPtSer/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.