What does ICD-10 code L04 mean?

ICD-10 code L04 is the standardized code used for acute lymphadenitis in medical records and coding systems.

When is ICD-10 code L04 used?

Doctors, hospitals, and insurers may use ICD-10 code L04 when recording acute lymphadenitis in a standardized format. This entry may also act as a broader category that points toward more specific child codes.

Does ICD-10 code L04 confirm a diagnosis?

No. A code helps standardize documentation and claims, but it should not be read as a substitute for a clinician's full assessment.

ICD10

ICD-10 Code L04: Acute lymphadenitis

Name: ICD-10 Code L04: Acute lymphadenitis
Creator: HealthAssure Clinical Team
Published: 2026-05-21T06:16:27.949Z

L04 is an ICD-10 diagnosis entry used to group records related to Acute lymphadenitis. You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen. ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Diseases of the skin and subcutaneous tissue (L00-L99).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Diseases of the skin and subcutaneous tissue (L00-L99).

When is it used?

May be used when a clinician documents acute lymphadenitis in a patient's medical record.
May appear in hospital records, claims, referrals, and clinical documentation.
This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.

What it does not mean

A code alone does not explain severity, treatment plan, or outcome.
A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
This entry may represent a broader category rather than the most specific billable code.

Code hierarchy

chapter

12Diseases of the skin and subcutaneous tissue (L00-L99)

block

L00-L08Infections of the skin and subcutaneous tissue

currentL00-L08

Official coding notes

Includes

abscess (acute) of lymph nodes, except mesenteric
acute lymphadenitis, except mesenteric

Excludes1 (do not code together)

chronic or subacute lymphadenitis, except mesenteric (I88.1)
enlarged lymph nodes (R59.-)
human immunodeficiency virus [HIV] disease resulting in generalized lymphadenopathy (B20)
lymphadenitis NOS (I88.9)
nonspecific mesenteric lymphadenitis (I88.0)

Where you may see this code

You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.

Related specialists

Dermatologist

Sibling codes

L00Staphylococcal scalded skin syndromebillable L01Impetigo L02Cutaneous abscess, furuncle and carbuncle L03Cellulitis and acute lymphangitis L05Pilonidal cyst and sinus L08Other local infections of skin and subcutaneous tissue

Coding guidelines

Compatibility

Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.

Legacy codes

L04

Replacement codes

L04.0 — Acute lymphadenitis of face, head and neckL04.1 — Acute lymphadenitis of trunkL04.2 — Acute lymphadenitis of upper limbL04.3 — Acute lymphadenitis of lower limbL04.8 — Acute lymphadenitis of other sitesL04.9 — Acute lymphadenitis, unspecified

Common synonyms

Acute lymphadenitis

Frequently asked questions

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. 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.