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LOINC Code 77366-3: Metanephrine.free and Normetanephrine.free and 3-Methoxytyramine.free panel

77366-3 is a LOINC code used to identify Metanephrine.free and Normetanephrine.free and 3-Methoxytyramine.free panel 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 Metanephrine.free & Normetanephrine.free & 3-Methoxytyramine.free panel. It is commonly used with the system or sample type Ser/Plas.

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 Metanephrine.free & Normetanephrine.free & 3-Methoxytyramine.free panel. It is commonly used with the system or sample type Ser/Plas.

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: Order
  • Panel type: Panel

What it does not mean

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

Key facts

Metanephrine.free and Normetanephrine.free and 3-Methoxytyramine.free panel - Serum or Plasma
Metanephrine.free & Normetanephrine.free & 3-Methoxytyramine.free panel
Measurement of O-methylated catecholamine metabolites (MNs), including free metanephrine (MN), free normetanephrine (NMN) and free 3-methoxytyramine (3-MT), levels in serum or plasma is performed for the biochemical diagnosis of pheochromocytoma.[PMID17712005] Additionally, concentrations of MNs are strongly correlated with tumor size.[PMID: 11041903]
3Me-tyramine; Chemistry; Dopamine metabolite; FR; Free 3-MT; Free MN, NMN and 3-MT; III; Metaneph; Metaneph Free; Metanephrne; Metenephrine; Non-protein bound; Normeta; Normetaneph; Normetaneph Free; Normetanephrn; Pan; PANEL.CHEMISTRY; Panl; Pl; Plasma; Plsm; Pnl; Point in time; Random; SerP; SerPl; SerPlas; Serum; Serum or plasma; SR; Unconjugated metanephrine; Unconjugated normetanephrine

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

Metanephrine.free and Normetanephrine.free and 3-Methoxytyramine.free panelMetanephrine.free and Normetanephrine.free and 3-Methoxytyramine.free panel - Serum or PlasmaFree MN, NMN and 3-MT SerPlMetanephrine.free & Normetanephrine.free & 3-Methoxytyramine.free panelPANEL.CHEMFree metanephrine, normetanephrine, and 3-Methoxytyramine panel, Blood-

Frequently asked questions

Code details

Code77366-3
SystemLOINC
Display nameMetanephrine.free and Normetanephrine.free and 3-Methoxytyramine.free panel
DescriptionMetanephrine.free & Normetanephrine.free & 3-Methoxytyramine.free panel
Short nameFree MN, NMN and 3-MT SerPl
ComponentMetanephrine.free & Normetanephrine.free & 3-Methoxytyramine.free panel
Property-
TimingPt
System (specimen)Ser/Plas
Scale-
ClassPANEL.CHEM
StatusACTIVE
Order/ObservationOrder

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.52
Last changed2.63

Consumer names

Free metanephrine, normetanephrine, and 3-Methoxytyramine panel, Blood

Part names

Metanephrine.free & Normetanephrine.free & 3-Methoxytyramine.free panel-PtSer/PlasMetanephrine.free and Normetanephrine.free and 3-Methoxytyramine.free panelPoint in time (spot)Serum or 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.