LOINCActiveObservation

LOINC Code 20991-6: Antithrombin (PPP) [Interp]

20991-6 is a LOINC code used to identify Antithrombin (PPP) [Interp] 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 Antithrombin. It is commonly used with the system or sample type PPP.

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 Antithrombin. It is commonly used with the system or sample type PPP.

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

  • Antithrombin [Interpretation] in Platelet poor plasma
  • Antithrombin
  • Anti thrombin; Antithrm; Antithrombin III; Antithrombn; AT; AT III; ATIII; COAGULATION; Hematology; Heme; Heparin cofactor I; Impression; Impression/interpretation of study; Impressions; Interp; Interpretation; Nominal; Plas; Platelet poor plasma; Point in time; Random; Thrombin inhibitor I

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

Antithrombin (PPP) [Interp]Antithrombin [Interpretation] in Platelet poor plasmaAT III PPP-ImpAntithrombinCOAGAntithrombin, BloodImp

Frequently asked questions

Code details

Code20991-6
SystemLOINC
Display nameAntithrombin (PPP) [Interp]
DescriptionAntithrombin
Short nameAT III PPP-Imp
ComponentAntithrombin
PropertyImp
TimingPt
System (specimen)PPP
ScaleNom
ClassCOAG
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0m
Last changed2.73

Consumer names

Antithrombin, Blood

Part names

AntithrombinImpPtPPPNomImpression/interpretation of studyPoint in time (spot)Platelet poor 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.

LOINC Code 20991-6 | HealthAssure