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.

LOINCActiveObservation

LOINC Code 58521-6: C peptide 9th specimen post Unsp challenge [Mass/Vol]

Name: LOINC Code 58521-6: C peptide 9th specimen post Unsp challenge [Mass/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:39.275Z

58521-6 is a LOINC code used to identify C peptide 9th specimen post Unsp challenge [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 C peptide^9th specimen post XXX challenge. 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 C peptide^9th specimen post XXX challenge. 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: Observation

What it does not mean

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

Key facts

C peptide [Mass/volume] in Serum or Plasma --9th specimen post XXX challenge
C peptide^9th specimen post XXX challenge
After; CHEMISTRY.CHALLENGE TESTING; Connecting peptide of insulin; Level; Mass concentration; p chal; Pept; Pl; Plasma; Plsm; Point in time; Pro-insulin c peptide; PST; QNT; Quan; Quant; Quantitative; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; sp9; sp9 p chal; Spec; SR

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

C peptide 9th specimen post Unsp challenge [Mass/Vol]C peptide [Mass/volume] in Serum or Plasma --9th specimen post XXX challengeC peptide sp9 p chal SerPl-mCncC peptide^9th specimen post XXX challengeCHALC peptide 9th specimen after challenge, BloodMCnc

Frequently asked questions

Code details

Code58521-6

SystemLOINC

Display nameC peptide 9th specimen post Unsp challenge [Mass/Vol]

DescriptionC peptide^9th specimen post XXX challenge

Short nameC peptide sp9 p chal SerPl-mCnc

ComponentC peptide^9th specimen post XXX challenge

PropertyMCnc

TimingPt

System (specimen)Ser/Plas

ScaleQn

ClassCHAL

Example unitsug/L

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.32

Last changed2.70

Consumer names

C peptide 9th specimen after challenge, Blood

Part names

C peptide^9th specimen post XXX challengeMCncPtSer/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.