Acute lymphadenitis (L04) ICD-10-CM
The L04 code range covers acute lymphadenitis with 7 ICD-10-CM diagnosis codes. 6 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
- abscess (acute) of lymph nodes, except mesenteric
- acute lymphadenitis, except mesenteric
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Codes in the L04 Range 7 codes · 6 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the L04 range.
Lymphocele
Cystic mass containing lymph from diseased lymphatic channels or following surgical trauma or other injury.
About the L04 Code Range
The ICD-10 codes under L04 are used to classify cases of acute lymphadenitis, an infection causing sudden swelling and inflammation of lymph nodes. These codes specify the affected body region to improve diagnosis accuracy and treatment tracking.
Acute lymphadenitis, also known as acute cervical lymphadenitis or lymph node abscess, occurs in various locations such as the face, head, and neck (L04.0), trunk (L04.1), upper limbs (L04.2), and lower limbs (L04.3). These terms help medical coders identify the exact site of infection, which is essential for precise billing and patient care. The code L04.8 covers acute lymphadenitis at other specified sites, while L04.9 is used when the site is unspecified, including conditions like acute abscess lymph node or lymphadenopathy co-occurring with HIV infection. Understanding these distinctions aids in selecting the correct ICD-10 code for acute lymphadenitis and related infections in skin and subcutaneous tissues.
Questions About This Page
How many billable codes are in the L04 range?
Of the 7 codes in this range, 6 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the L04 range classify?
The range classifies acute lymphadenitis. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
