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 517-3: Trimethoprim+Sulfamethoxazole Disk diffusion (KB) [Susc]

Name: LOINC Code 517-3: Trimethoprim+Sulfamethoxazole Disk diffusion (KB) [Susc]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:35.013Z

517-3 is a LOINC code used to identify Trimethoprim+Sulfamethoxazole Disk diffusion (KB) [Susc] 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 Trimethoprim+Sulfamethoxazole. It is commonly used with the system or sample type Isolate.

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 Trimethoprim+Sulfamethoxazole. It is commonly used with the system or sample type Isolate.

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
Method: Agar diffusion

What it does not mean

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

Key facts

Trimethoprim+Sulfamethoxazole [Susceptibility] by Disk diffusion (KB)
Trimethoprim+Sulfamethoxazole
Acetylsulfamethoxazole; ANTIBIOTIC SUSCEPTIBILITIES; AST; Bactrim; c202; c203; c223; c242; C61; C62; Cotrim; Cotrimoxazole; Co-trimoxazole; Disk diffusion; Gantanol; ID; Infectious Disease; InfectiousDisease; Islt; Isol; KB; Kirby-bauer; Point in time; Polytrim; Primsol; Proloprim; Random; Septra; SMX; SMX-TMP; Sulfa; Sulfamethox; Sus; Suscept; Susceptibilities; Susceptibility; Susceptibilty; SXT; TMP; TMP SMX; TMP-SMX; Trimeth; Trimpex

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

Trimethoprim+Sulfamethoxazole Disk diffusion (KB) [Susc]Trimethoprim+Sulfamethoxazole [Susceptibility] by Disk diffusion (KB)TMP SMX Islt KBTrimethoprim+SulfamethoxazoleABXBACTSusceptibility to Trimethoprim+SulfamethoxazoleSusc

Frequently asked questions

Code details

Code517-3

SystemLOINC

Display nameTrimethoprim+Sulfamethoxazole Disk diffusion (KB) [Susc]

DescriptionTrimethoprim+Sulfamethoxazole

Short nameTMP SMX Islt KB

ComponentTrimethoprim+Sulfamethoxazole

PropertySusc

TimingPt

System (specimen)Isolate

ScaleOrdQn

MethodAgar diffusion

ClassABXBACT

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0

Last changed2.73

Consumer names

Susceptibility to Trimethoprim+Sulfamethoxazole

Part names

Trimethoprim+SulfamethoxazoleSuscPtIsolateOrdQnAgar diffusionSusceptibility (microorganisms)Point in time (spot)Disk diffusion (KB)

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.