2026 ICD-10-CM Diagnosis Code L43.3Subacute (active) lichen planus
ICD-10-CM Codes›L00–L99›L40-L45›L43
- Billable — Valid for Submission
- Not Chronic
L43.3 is a billable ICD-10-CM diagnosis code for subacute (active) lichen planus. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 606 through 607. Coders also document this condition as subacute active lichen planus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified inflammatory condition of skin.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Subacute active lichen planus
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Lichen planus tropicus
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- subacute (active) - L43.3
- tropicus - L43.3
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Lichen
- planus (chronicus)
- subacute (active)
- Lichen
- planus (chronicus)
- tropicus
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
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)Atrophic Lichen Planus
a rare form of lichen planus that is characterized by well-demarcated, white-bluish papules or plaques with central atrophy.Bullous Lichen Planus
a rare form of lichen planus that is characterized by the formation of vesico-bullous lesions on top of preexisting lichen planus papules or on normal skin.Hypertrophic Lichen Planus
a form of lichen planus that is characterized by plaques of markedly thickened skin that is often extremely pruritic and localized to the lower legs. it can result in permanent pigmentation and scarring.Lichen Planus
a chronic, recurrent, pruritic inflammatory disorder of unknown etiology that affects the skin and mucus membranes. it presents with rashes and papules that tend to resolve spontaneously. it may be associated with hepatitis c. certain drugs that contain arsenic or bismuth are associated with reactions mimicking lichen planus.Lichen Planus-Like Keratosis|Lichenoid Keratosis
a benign intraepidermal squamoproliferative neoplasm characterized by irregular acanthosis, hyperkeratosis, parakeratosis, and prominent chronic inflammation.Lichenoid Drug Eruption|Drug-induced Lichen Planus|Drug-induced Lichen Planus
a red or violaceous flat-topped, papular eruption that is induced by exposure to a variety of medications or environmental agents.Oral Lichen Planus
a chronic, autoimmune inflammatory condition of the mucous membranes in the oral cavity that affects approximately two percent of the population and is most often seen in middle aged women. it is characterized by white, lacy patches; red, swollen tissue; papules and plaques; or open sores. the lesions are typically bilateral.
Patient EducationClinical
Skin Conditions
Your skin is your body's largest organ. It covers the entire outside of your body. There are many ways that your skin protects your body and helps keep you healthy. For example, it:
The full article covers:
- What does your skin do?
- What problems and conditions can affect your skin?
- How can I keep my skin healthy?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert L43.3 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About L43.3Overview
Is L43.3 (Lichen planus) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report subacute (active) lichen planus on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does L43.3 group to?
When subacute (active) lichen planus is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, with relative weights from 0.9064 to 1.5132 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of L43.3?
Under the General Equivalence Mappings, subacute (active) lichen planus converts to ICD-9-CM 697.0 (lichen planus). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
