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.

LOINC

LOINC Code 64790-9: What month and year did your child first have this type of operation [Date and time] [PhenX]

Name: LOINC Code 64790-9: What month and year did your child first have this type of operation [Date and time] [PhenX]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:44.549Z

64790-9 is a LOINC code used to identify What month and year did your child first have this type of operation [Date and time] [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 When did your child first have this type of operation. 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 When did your child first have this type of operation. 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

What month and year did your child first have this type of operation [Date and time] [PhenX]
When did your child first have this type of operation
Date and time; Operation straighten eyes date; Point in time; QNT; Quan; Quant; Quantitative; Random; Time stamp; Timestamp

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

What month and year did your child first have this type of operation [Date and time] [PhenX]Operation straighten eyes date PhenXWhen did your child first have this type of operationPHENXTmStpPt^Patient

Frequently asked questions

Code details

Code64790-9

SystemLOINC

Display nameWhat month and year did your child first have this type of operation [Date and time] [PhenX]

DescriptionWhen did your child first have this type of operation

Short nameOperation straighten eyes date PhenX

ComponentWhen did your child first have this type of operation

PropertyTmStp

TimingPt

System (specimen)^Patient

ScaleQn

MethodPhenX

ClassPHENX

StatusTRIAL

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.36

Last changed2.65

Part names

When did your child first have this type of operationTmStpPt^PatientQnPhenXWhat month and year did your child first have this type of operationTime Stamp (Date and Time)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.