LOINC

LOINC Code 64843-6: Letter on line read by the patient [PhenX]

64843-6 is a LOINC code used to identify Letter on line read by the patient [PhenX] 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 Letter on line read by the patient. 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 Letter on line read by the patient. 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: TRIAL
  • Method: PhenX

What it does not mean

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

Key facts

  • Letter on line read by the patient [PhenX]
  • Letter on line read by the patient
  • Finding; Findings; Nominal; Point in time; Random; Visual acuity letter line

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

Letter on line read by the patient [PhenX]Visual acuity letter line PhenXLetter on line read by the patientPHENXFindPt^Patient

Frequently asked questions

Code details

Code64843-6
SystemLOINC
Display nameLetter on line read by the patient [PhenX]
DescriptionLetter on line read by the patient
Short nameVisual acuity letter line PhenX
ComponentLetter on line read by the patient
PropertyFind
TimingPt
System (specimen)^Patient
ScaleNom
MethodPhenX
ClassPHENX
StatusTRIAL

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.36
Last changed2.65

Part names

Letter on line read by the patientFindPt^PatientNomPhenXFindingPoint 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 64843-6 | HealthAssure