L56.4 Polymorphous light eruption

The ICD-10-CM code for Polymorphous light eruption is L56.4 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

12: Diseases of the skin and subcutaneous tissue (L00-L99)

Section

L55-L59: Radiation-related disorders of the skin and subcutaneous tissue (L55-L59)

Category L56

9 codes (8 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to L56.4:

• Prurigo (ferox) (gravis) (Hebrae) (Hebra's) (mitis) (simplex) › estivalis
• Eruption › polymorphous light (sun)
• Eruption › Hutchinson, summer
• Hydroa › aestivale
• Hydroa › vacciniforme
• Hutchinson's › disease, meaning › summer eruption or summer prurigo
• Hutchinson's › disease, meaning › prurigo estivalis

U.S. Hospital Utilization

• An estimated 55 U.S. inpatient stays in 2018 included L56.4 among the documented diagnoses.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Pressure ulcer stages—L89 identifies site/stage; code all ulcers

a. Pressure ulcer stage codes 1) Pressure ulcer stages Codes in category L89, Pressure ulcer, identify the site and stage of the pressure ulcer. The ICD-10-CM classifies pressure ulcer stages based on severity, which is designated by stages 1-4, deep tissue pressure injury, unspecified stage, and unstageable. Assign as many codes from category L89 as needed to identify all the pressure ulcers the patient has, if applicable. See Section I.B.14. for pressure ulcer stage documentation by clinicians other than patient's provider.

Unstageable pressure ulcers—L89.--0 based on clinical documentation

2) Unstageable pressure ulcers Assignment of the code for unstageable pressure ulcer (L89.--0) should be based on the clinical documentation. These codes are used for

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)

Cite This Page

Reference L56.4 with the canonical source and edition:

L56.4 — Polymorphous light eruption. ICD-10 Coding Pro (ICD-10-CM FY2026). https://icd10codingpro.com/codes/L56.4

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