Lichen planus (L43) ICD-10-CM
The L43 code range covers lichen planus 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.
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.
- lichen planopilaris L66.1
Codes in the L43 Range 7 codes · 6 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the L43 range.
Lichen Planus
An inflammatory, pruritic disease of the skin and mucous membranes, which can be either generalized or localized. It is characterized by distinctive purplish, flat-topped papules having a predilection for the trunk and flexor surfaces. The lesions may be discrete or coalesce to form plaques. Histologically, there is a saw-tooth pattern of epidermal hyperplasia and vacuolar alteration of the basal layer of the epidermis along with an intense upper dermal inflammatory infiltrate composed predominantly of T-cells. Etiology is unknown.
Lichen Planus, Oral
Oral lesions accompanying cutaneous lichen planus or often occurring alone. The buccal mucosa, lips, gingivae, floor of the mouth, and palate are usually affected (in a descending order of frequency). Typically, oral lesions consist of radiating white or gray, velvety, threadlike lines, arranged in a reticular pattern, at the intersection of which there may be minute, white, elevated dots or streaks (Wickham's striae). (Jablonski, Illustrated Dictionary of Dentistry)
Onycholysis
Separation of nail plate from the underlying nail bed. It can be a sign of skin disease, infection (such as ONYCHOMYCOSIS) or tissue injury.
Onychomycosis
A fungal infection of the nail, usually caused by DERMATOPHYTES; YEASTS; or nondermatophyte MOLDS.
About the L43 Code Range
The ICD-10 code L43 identifies lichen planus, a distinct inflammatory skin condition affecting various body parts. This group of codes is specifically used to document different forms and manifestations of lichen planus, ranging from typical cases to specialized variants like hypertrophic, bullous, or drug-related types.
The ICD-10 code for lichen planus (L43) covers the general diagnosis, while subcodes address particular presentations. For example, L43.0 refers to hypertrophic lichen planus, including thickened eruptions commonly on the vulva or oral regions. L43.1 denotes bullous lichen planus, characterized by blister formation. Drug-induced lichenoid reactions, which mimic classic lichen planus but are caused by medications, fall under L43.2. Other specified types, including ulcerative, annular, or pigmentary variants, are captured by L43.8. When the lichen planus form is unspecified or unclear, L43.9 is applied. These codes help medical coders accurately identify the exact clinical form, such as “oral lichenoid reaction” or “genital lichen planus,” ensuring precise documentation and treatment tracking.
Questions About This Page
How many billable codes are in the L43 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 L43 range classify?
The range classifies lichen planus. 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.
