ICD10BillableValid for clinical use
ICD-10 Code L91.0: Hypertrophic scar
Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026
What is this code?
ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the skin and subcutaneous tissue (L00-L99).
When is it used?
- May be used when a clinician documents hypertrophic scar in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code can be used as a clinically usable diagnosis entry in standardized coding workflows.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
Code hierarchy
chapter
12Diseases of the skin and subcutaneous tissue (L00-L99)
block
L80-L99Other disorders of the skin and subcutaneous tissue
category
L91Hypertrophic disorders of skin
currentL91
Official coding notes
Inclusion terms
- Keloid
- Keloid scar
Excludes2 (may code together if documented)
- acne keloid (L73.0)
- scar NOS (L90.5)
Where you may see this code
You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.
Related specialists
Dermatologist
Related codes
Sibling codes
Coverage-related procedures and services
CPT 97034high
APPLICATION OF A MODALITY TO 1 OR MORE AREAS; CONTRAST BATHS, EACH 15 MINUTES
Source: CMS coverage guidance
CPT 97032high
APPLICATION OF A MODALITY TO 1 OR MORE AREAS; ELECTRICAL STIMULATION (MANUAL), EACH 15 MINUTES
Source: CMS coverage guidance
CPT 97026high
APPLICATION OF A MODALITY TO 1 OR MORE AREAS; INFRARED
Source: CMS coverage guidance
CPT 97033high
APPLICATION OF A MODALITY TO 1 OR MORE AREAS; IONTOPHORESIS, EACH 15 MINUTES
Source: CMS coverage guidance
CPT 97018high
APPLICATION OF A MODALITY TO 1 OR MORE AREAS; PARAFFIN BATH
Source: CMS coverage guidance
CPT 97035high
APPLICATION OF A MODALITY TO 1 OR MORE AREAS; ULTRASOUND, EACH 15 MINUTES
Source: CMS coverage guidance
Mapped diagnoses and classifications
SNOMED_CT 403412007high
Ear-lobe keloid
Source: SNOMED International ICD-10 map
SNOMED_CT 19843006high
Hypertrophic scar
Source: SNOMED International ICD-10 map
SNOMED_CT 447046001high
Hypertrophic scar of upper arm
Source: SNOMED International ICD-10 map
SNOMED_CT 239191000high
Hypertrophic scarring of skin donor site
Source: SNOMED International ICD-10 map
SNOMED_CT 403685009high
Hypertrophic surgical scar
Source: SNOMED International ICD-10 map
SNOMED_CT 33659008high
Keloid scar
Source: SNOMED International ICD-10 map
Coding guidelines
Compatibility
Legacy and official ICD code match exactly.
Legacy codes
L91.0
Common synonyms
Hypertrophic scar
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.