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ICD-10-CM 2027 diagnosis code

L56.4Polymorphous light eruption

✓ Billable / specific

L56.4 is a valid, billable ICD-10-CM code for polymorphous light eruption. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About L56.4

L56.4 is the ICD-10-CM diagnosis code for Polymorphous light eruption. It belongs to category L56 (other acute skin changes due to ultraviolet radiation), block L55-L59 (Radiation-related disorders of the skin and subcutaneous tissue) and chapter 12 (diseases of the skin and subcutaneous tissue). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within L56 (other acute skin changes due to ultraviolet radiation), L56.4 is specifically for Polymorphous light eruption. Related codes cover drug phototoxic response (L56.0), drug photoallergic response (L56.1), Photocontact dermatitis [berloque dermatitis] (L56.2), solar urticaria (L56.3), disseminated superficial actinic porokeratosis (DSAP) (L56.5), other specified acute skin changes due to ultraviolet radiation (L56.8) and acute skin change due to ultraviolet radiation, unspecified (L56.9).

Use an additional code to identify the source of the ultraviolet radiation (W89, X32).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 606 (Minor Skin Disorders with MCC, relative weight 1.5728) and DRG 607 (Minor Skin Disorders without MCC, relative weight 0.8772), in MDC 09 (Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 692.82 (dermatitis due to other radiation).

Notes that apply from higher levels

Instructions written at a parent level also apply to L56.4.

› From L56 Other acute skin changes due to ultraviolet radiation
Use additional code
  • code to identify the source of the ultraviolet radiation (W89, X32)

Broader instructions also apply from Chapter 12: Diseases of the skin and subcutaneous tissue.

Alphabetic index entries

7 entries

Terms in the official ICD-10-CM index that lead to L56.4.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

MDC 09 · Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast

ICD-9-CM equivalent

Converter →
  • 692.82Dermatitis due to other radiationapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about L56.4

Is L56.4 billable?

Yes. L56.4 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can L56.4 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict L56.4 as a principal diagnosis.

Is L56.4 a CC or MCC?

No. L56.4 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does L56.4 group to?

L56.4 is used in the MS-DRG v44.0 logic for MS-DRG 606 (Minor Skin Disorders with MCC) and MS-DRG 607 (Minor Skin Disorders without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for L56.4?

The CMS General Equivalence Mappings map L56.4 to ICD-9-CM 692.82.