Alphabetic Index FY2027

L04.0

Acute lymphadenitis of face, head and neck

FY2027Chapter 12: Diseases of the skin and subcutaneous tissue/L00–L08 Infections of the skin and subcutaneous tissue

BillableComplete code, valid to report
Care settingsHome Health Primary · Wound

L04.0 (also written L040) is a billable ICD-10-CM diagnosis code for acute lymphadenitis of face, head and neck. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 6 codes in category L04 (Acute lymphadenitis). The Alphabetic Index lists it under 7 entries. Its coding notes include a Use additional code instruction, 5 Excludes1 entries and 23 Excludes2 entries.

Use additional code

Add the listed code as a secondary code, if known.

Also from chapter/block level (1 note)
Inherited from L00–L08 Infections of the skin and subcutaneous tissue
  • code (B95-B97) to identify infectious agent.

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from L04 Acute lymphadenitis
  • 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)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (23 notes)
Inherited from L00–L08 Infections of the skin and subcutaneous tissue
  • hordeolum (H00.0)
  • infective dermatitis (L30.3)
  • local infections of skin classified in Chapter 1
  • lupus panniculitis (L93.2)
  • panniculitis NOS (M79.3)
  • panniculitis of neck and back (M54.0-)
  • Perlèche NOS (K13.0)
  • Perlèche due to candidiasis (B37.0)
  • Perlèche due to riboflavin deficiency (E53.0)
  • pyogenic granuloma (L98.0)
  • relapsing panniculitis [Weber-Christian] (M35.6)
  • viral warts (B07.-)
  • zoster (B02.-)
Inherited from Chapter 12 Diseases of the skin and subcutaneous tissue
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • lipomelanotic reticulosis (I89.8)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • viral warts (B07.-)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Home Health Primary

Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the Wound clinical group.

Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026

Includes

Further defines or gives examples of the content of the category.

Inherited from L04 Acute lymphadenitis
  • abscess (acute) of lymph nodes, except mesenteric
  • acute lymphadenitis, except mesenteric

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 7 entries