LOINCActiveBoth

LOINC Code 4636-7: Free Hemoglobin (U) [Mass/Vol]

4636-7 is a LOINC code used to identify Free Hemoglobin (U) [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 Hemoglobin.free. It is commonly used with the system or sample type Urine.

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.free. 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

What it does not mean

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

Key facts

  • Free Hemoglobin [Mass/volume] in Urine
  • Hemoglobin.free
  • FR; Haemoglobin; Hb; HEMATOLOGY/CELL COUNTS; Hgb; Hgb Free; Level; Mass concentration; Non-protein bound; Point in time; QNT; Quan; Quant; Quantitative; Random; 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

Free Hemoglobin (U) [Mass/Vol]Free Hemoglobin [Mass/volume] in UrineHgb Free Ur-mCncHemoglobin.freeHEM/BCFree hemoglobin, UrineMCnc

Frequently asked questions

Code details

Code4636-7
SystemLOINC
Display nameFree Hemoglobin (U) [Mass/Vol]
DescriptionHemoglobin.free
Short nameHgb Free Ur-mCnc
ComponentHemoglobin.free
PropertyMCnc
TimingPt
System (specimen)Urine
ScaleQn
ClassHEM/BC
Example unitsmg/dL
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0
Last changed2.73

Consumer names

Free hemoglobin, Urine

Part names

Hemoglobin.freeMCncPtUrineQnFree HemoglobinMass ConcentrationPoint 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.

LOINC Code 4636-7 | HealthAssure