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.

LOINCActiveBoth

LOINC Code 17864-0: Calcium.ionized ISE [Mass/Vol]

Name: LOINC Code 17864-0: Calcium.ionized ISE [Mass/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-25T17:13:11.347Z

17864-0 is a LOINC code used to identify Calcium.ionized ISE [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 Calcium.ionized. It is commonly used with the system or sample type Ser/Plas.

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 Calcium.ionized. 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: Both
Method: ISE

What it does not mean

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

Key facts

Calcium.ionized [Mass/volume] in Serum or Plasma by Ion-selective membrane electrode (ISE)
Calcium.ionized
Ca; Ca-I; Cal; Calcium active; Calcium free; Chemistry; Coagulation factor I; ICA; Ion; Ion selective membrane electode; Ion selective membrane electrode; Ion-selective electrode; Level; Mass concentration; Pl; Plasma; Plsm; Point in time; QNT; Quan; Quant; Quantitative; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; SR; UniversalLabOrders

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.

Related SNOMED CT concepts

705114005SNOMED CT mapping for Calcium.ionized ISE [Mass/Vol] (17864-0)

Related observations and tests

SNOMED_CT 705114005high

LOINC Code System

Source: LOINC-SNOMED cooperation package

Common synonyms

Calcium.ionized ISE [Mass/Vol]Calcium.ionized [Mass/volume] in Serum or Plasma by Ion-selective membrane electrode (ISE)Ca-I SerPl ISE-mCncCalcium.ionizedCHEMCalcium.ionized, BloodMCnc

Frequently asked questions

Code details

Code17864-0

SystemLOINC

Display nameCalcium.ionized ISE [Mass/Vol]

DescriptionCalcium.ionized

Short nameCa-I SerPl ISE-mCnc

ComponentCalcium.ionized

PropertyMCnc

TimingPt

System (specimen)Ser/Plas

ScaleQn

MethodISE

ClassCHEM

Example unitsmg/dL

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0l

Last changed2.73

Consumer names

Calcium.ionized, Blood

Part names

Calcium.ionizedMCncPtSer/PlasQnISEMass ConcentrationPoint in time (spot)Serum or PlasmaIon-selective membrane electrode (ISE)

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.