2026 ICD-10-CM Diagnosis Code L99Other disorders of skin and subcutaneous tissue in diseases classified elsewhere
ICD-10-CM Codes›L00–L99›L80-L99›L99
- Billable — Valid for Submission
- Not Chronic
L99 is a billable ICD-10-CM diagnosis code for other disorders of skin and subcutaneous tissue in diseases classified elsewhere. 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. The code is a manifestation code that cannot be reported as the principal diagnosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified skin disorders.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for L99.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute Chagas' disease
- African trypanosomiasis affecting skin
- Amyloidosis cutis dyschromia
- Amyloidosis limited to skin
- Behcet disease of skin
- Chagas' exanthem
- Cutaneous complication of rheumatoid disease
- Cutaneous complication of systemic sclerosis
- Dermatosis resulting from vascular insufficiency
- Disorder of skin co-occurrent with human immunodeficiency virus infection
- Disorder of skin due to human immunodeficiency virus infection
- Human immunodeficiency virus modified skin disease
- Metabolic and nutritional disorders affecting skin
- Non-specific cutaneous reaction in Hodgkin's disease
- Primary localized cutaneous amyloidosis
- Rheumatoid neutrophilic dermatitis
- Skin disorder with AIDS
- Skin involvement in bacterial endocarditis
- Skin lesion in drug addict
- Small vessel thrombosis of skin
- Spinal cord defect affecting skin
- Systemic disease affecting skin
- Trypanosomiasis affecting skin
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Code First
- underlying disease, such as:
- amyloidosis E85
Type 1 Excludes
- skin disorders in diabetes E08 E13
- skin disorders in gonorrhea A54.89
- skin disorders in syphilis A51.31 A52.79
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
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.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 L99 to ICD-9-CMHistory
Code HistoryHistory
Questions About L99Overview
Is L99 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other disorders of skin and subcutaneous tissue in diseases classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does L99 group to?
On inpatient claims, other disorders of skin and subcutaneous tissue in diseases classified elsewhere maps to MS-DRG 606, 607, with relative weights from 0.9064 to 1.5132 depending on complications. Higher weights mean higher Medicare reimbursement.
Can L99 be a principal diagnosis?
No. This is a manifestation code: other disorders of skin and subcutaneous tissue in diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
What is the ICD-9 equivalent of L99?
Under the General Equivalence Mappings, other disorders of skin and subcutaneous tissue in diseases classified elsewhere converts to ICD-9-CM 701.8 (skin hypertro/atroph NEC) and 709.8 (skin disorders NEC). 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.
