2026 ICD-10-CM Diagnosis Code L91.0Hypertrophic scar
ICD-10-CM Codes›L00–L99›L80-L99›L91
- Billable — Valid for Submission
- Not Chronic
L91.0 is a billable ICD-10-CM diagnosis code for hypertrophic scar. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified skin disorders.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acne scar
- Acne scars - mixed atrophic and hypertrophic
- Acroosteolysis
- Acroosteolysis, keloid-like lesions, premature aging syndrome
- Contracture scar
- Disorder of skin donor site
- Ear-lobe keloid
- Hereditary acroosteolysis
- Hypertrophic acne scar
- Hypertrophic scar
- Hypertrophic scar of upper arm
- Hypertrophic scarring of skin donor site
- Hypertrophic surgical scar
- Keloid acne scar
- Keloid scar
- Keloidal surgical scar
- Surgical scar finding
- X-linked keloid scarring, reduced joint mobility, increased optic cup-to-disc ratio syndrome
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Keloid
- Keloid scar
Type 2 Excludes
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.
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- scar - L91.0
- Kelis - L91.0
- Keloid, cheloid - L91.0
- Keloma - L91.0
- Scar, scarring - See Also: Cicatrix; - L90.5
- cheloid - L91.0
- hypertrophic - L91.0
- keloid - L91.0
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Hypertrophy, hypertrophic
- scar
- Kelis
- Keloid, cheloid
- Keloid, cheloid
- Hawkin's
- Keloid, cheloid
- scar
- Keloma
- Scar, scarring
- cheloid
- Scar, scarring
- hypertrophic
- Scar, scarring
- keloid
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Hypertrophic Scar
a permanent mark on the skin caused by deposits of excessive amounts of collagen during wound healing. it is elevated and does not extend beyond the original boundaries of the wound; the elevation may stabilize or regress spontaneously.Acroosteolysis
a condition that is characterized by degeneration of the distal phalanges.
Patient EducationClinical
Scars
A scar is a permanent patch of skin that grows over a wound. It forms when your body heals itself after a cut, scrape, burn, or sore. You can also get scars from surgery that cuts through the skin, infections like chickenpox, or skin conditions like acne.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert L91.0 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About L91.0Overview
Is L91.0 (Hypertrophic disorders of skin) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report hypertrophic scar on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does L91.0 group to?
When hypertrophic scar 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 L91.0?
Under the General Equivalence Mappings, hypertrophic scar converts to ICD-9-CM 701.4 (keloid scar). The mapping is a direct match.
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.
