LOINCActiveObservation

LOINC Code 4555-9: Hemoglobin A3 (Bld) [Mass fraction]

4555-9 is a LOINC code used to identify Hemoglobin A3 (Bld) [Mass fraction] 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 Hemoglobin A3/Hemoglobin.total. It is commonly used with the system or sample type Bld.

Reviewed by HealthAssure Clinical TeamUpdated 25 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 Hemoglobin A3/Hemoglobin.total. It is commonly used with the system or sample type Bld.

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

  • Hemoglobin A3/Hemoglobin.total in Blood
  • Hemoglobin A3/Hemoglobin.total
  • Blood; Haemoglobin; Hb; HEMATOLOGY/CELL COUNTS; Hgb; Hgb A3; Mass Fraction; Percent; Point in time; QNT; Quan; Quant; Quantitative; Random; Tot; Totl; WB; Whole blood

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

Hemoglobin A3 (Bld) [Mass fraction]Hemoglobin A3/Hemoglobin.total in BloodHgb A3 MFr BldHemoglobin A3/Hemoglobin.totalHEM/BCHemoglobin A3/Total Hgb, BloodMFr

Frequently asked questions

Code details

Code4555-9
SystemLOINC
Display nameHemoglobin A3 (Bld) [Mass fraction]
DescriptionHemoglobin A3/Hemoglobin.total
Short nameHgb A3 MFr Bld
ComponentHemoglobin A3/Hemoglobin.total
PropertyMFr
TimingPt
System (specimen)Bld
ScaleQn
ClassHEM/BC
Example units%
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0
Last changed2.70

Consumer names

Hemoglobin A3/Total Hgb, Blood

Part names

Hemoglobin A3/Hemoglobin.totalMFrPtBldQnMass fractionPoint in time (spot)Blood

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 4555-9 | HealthAssure