LOINCActiveObservation

LOINC Code 42798-9: Age at menarche

42798-9 is a LOINC code used to identify Age at menarche 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 Age at menarche. It is commonly used with the system or sample type ^Patient.

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 Age at menarche. It is commonly used with the system or sample type ^Patient.

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

  • Age at menarche
  • Age @ Menarche; MISC; Point in time; QNT; Quan; Quant; Quantitative; Random

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

Age at menarcheAge @ Menarche Time PatientMISCTimePt^PatientQn

Frequently asked questions

Code details

Code42798-9
SystemLOINC
Display nameAge at menarche
Short nameAge @ Menarche Time Patient
ComponentAge at menarche
PropertyTime
TimingPt
System (specimen)^Patient
ScaleQn
ClassMISC
Example unitsyears
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.16
Last changed2.73

Consumer names

Age at menarche

Part names

Age at menarcheTimePt^PatientQnTime (e.g. seconds)Point 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 42798-9 | HealthAssure