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  6. 2025 ICD-10-CM Code L91.0

2025 ICD-10-CM Diagnosis Code L91.0

Hypertrophic scar

ICD-10-CM Code:
L91.0
ICD-10 Code for:
Hypertrophic scar
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

L91.0 is a billable diagnosis code used to specify a medical diagnosis of hypertrophic scar. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2024 through September 30, 2025.

Code Classification

  • Diseases of the skin and subcutaneous tissue
    L00–L99
    • Other disorders of the skin and subcutaneous tissue
      L80-L99
      • Hypertrophic disorders of skin
        L91

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

  • Acne scar
  • Acne scar
  • 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
  • Keloid scar
  • Keloidal surgical scar
  • Surgical scar finding
  • X-linked keloid scarring, reduced joint mobility, increased optic cup-to-disc ratio syndrome

Clinical Classification

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

Other specified and unspecified skin disorders

CCSR Code: SKN007

Inpatient Default: Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

Clinical Information

  • 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.

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Inclusion Terms

Inclusion Terms
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.
  • Keloid
  • Keloid scar

Type 2 Excludes

Type 2 Excludes
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 Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Convert L91.0 to ICD-9-CM

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

Keloid scar

ICD-9-CM: 701.4

This is a direct match with no additional mapping qualifiers. The absence of a flag generally means the mapping is considered exact or precise. In other words, the ICD-10 code maps cleanly to the ICD-9 code without qualification, approximation, or needing multiple codes.

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Patient Education


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. Scars are often thicker, as well as pinker, redder, or shinier, than the rest of your skin.

How your scar looks depends on:

  • How big and deep your wound is
  • Where it is
  • How long it takes to heal
  • Your age
  • Your inherited tendency to scar

Scars usually fade over time but never go away completely. If the way a scar looks bothers you, various treatments might minimize it. These include surgical revision, dermabrasion, laser treatments, injections, chemical peels, and creams.


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.

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.