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L55.9 ICD-10-CM Code: Sunburn, unspecified

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 606 — MINOR SKIN DISORDERS WITH MCC (MDC 09)
  • MS-DRG 607 — MINOR SKIN DISORDERS WITHOUT MCC (MDC 09)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coder workflow for L55.9

MedCoder structured workflow — derived from this code’s own official record

Before you code L55.9

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, L55.9 may be the appropriate code. Check the record for detail that supports a more specific sibling. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

    ReviewL55.0, L55.1, L55.2

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

Choose the right path

  1. Does the record document the detail a more specific sibling code needs?
    Yes → Review the specific siblings in this subcategory.
    No → Continue — L55.9 is appropriate when the documentation goes no further.

    ReviewL55.0, L55.1, L55.2

Consider L55.9. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The provider documents the condition in the terms of this code’s title and records no further detail.

Coding question: Is a more specific sibling code supportable?

Path: Review the specific siblings in this subcategory and what each requires the record to state.

Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).

ReviewL55.0, L55.1, L55.2

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Sunburn, unspecified is a billable ICD-10-CM diagnosis code (L55.9).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name L55.9 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 4 Excludes1 notes across 2 chapters: K13.0 — Diseases of lips (via L55.-), T07 — Unspecified multiple injuries (via L55.-), T66 — Radiation sickness, unspecified (via L55.-), T67 — Effects of heat and light (via L55.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 15 Excludes2 notes across 3 chapters: L20 — Atopic dermatitis (via L55.-), L20-L30 — Dermatitis and eczema (L20-L30) (via L55.-), L21 — Seborrheic dermatitis (via L55.-), L22 — Diaper dermatitis (via L55.-), L23 — Allergic contact dermatitis (via L55.-), L24 — Irritant contact dermatitis (via L55.-), L25 — Unspecified contact dermatitis (via L55.-), L26 — Exfoliative dermatitis (via L55.-), L27 — Dermatitis due to substances taken internally (via L55.-), L28 — Lichen simplex chronicus and prurigo (via L55.-), L29 — Pruritus (via L55.-), L30 — Other and unspecified dermatitis (via L55.-), T20-T32 — Burns and corrosions (T20-T32) (via L55.-), T67 — Effects of heat and light (via L55.-), X32 — Exposure to sunlight (via L55.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

Named in the grouper logic of 2 MS-DRGs: DRG 606 (MDC 09), DRG 607 (MDC 09).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):SKN002 — Other specified inflammatory condition of skin (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Other specified inflammatory condition of skin).

L53.0 — Toxic erythema, L53.1 — Erythema annulare centrifugum, L53.2 — Erythema marginatum, L53.3 — Other chronic figurate erythema, L53.8 — Other specified erythematous conditions, L53.9 — Erythematous condition, unspecified, L54 — Erythema in diseases classified elsewhere, L55.0 — Sunburn of first degree, L55.1 — Sunburn of second degree, L55.2 — Sunburn of third degree, L66.1 — Lichen planopilaris, L66.10 — Lichen planopilaris, unspecified, L66.11 — Classic lichen planopilaris, L66.12 — Frontal fibrosing alopecia, L66.19 — Other lichen planopilaris, L70.0 — Acne vulgaris, L70.1 — Acne conglobata, L70.2 — Acne varioliformis, L70.3 — Acne tropica, L70.4 — Infantile acne, +145 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Sunburn”, “Heat”; these codes share that main term but sit in a different category of the Tabular List.

L56.8 — Other specified acute skin changes due to ultraviolet radiation (due to, tanning bed), L57.8 — Other skin changes due to chronic exposure to nonionizing radiation (due to, tanning bed, chronic), L59.0 — Erythema ab igne [dermatitis ab igne] (dermatitis or eczema), L74.0 — Miliaria rubra (rash), T67.01 — Heatstroke and sunstroke (fever), T67.02 — Exertional heatstroke (stroke, exertional), T67.09 — Other heatstroke and sunstroke (stroke, specified NEC), T67.1 — Heat syncope (syncope), T67.2 — Heat cramp (cramps), T67.3 — Heat exhaustion, anhydrotic (exhaustion, anhydrotic), T67.4 — Heat exhaustion due to salt depletion (exhaustion, due to, saltdepletion), T67.5 — Heat exhaustion, unspecified (exhaustion), T67.6 — Heat fatigue, transient (fatigue), T67.7 — Heat edema (edema), T67.8 — Other effects of heat and light (specified effect NEC), T67.9 — Effect of heat and light, unspecified

Contextual Map

Every relationship of L55.9 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run L55.9 with these 12 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

  • K13.0 — Diseases of lips[Excludes1](via L55.-): “cheilitis due to radiation-related disorders (L55-L59)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • T07 — Unspecified multiple injuries[Excludes1](via L55.-): “sunburn (L55.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • T66 — Radiation sickness, unspecified[Excludes1](via L55.-): “radiation related disorders of the skin and subcutaneous tissue (L55-L59)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • T67 — Effects of heat and light[Excludes1](via L55.-): “radiation-related disorders of the skin and subcutaneous tissue (L55-L59)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes2 notes (15)

  • L20 — Atopic dermatitis[Excludes2](via L55.-): “radiation-related disorders of the skin and subcutaneous tissue (L55-L59)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • L20-L30 — Dermatitis and eczema (L20-L30)[Excludes2](via L55.-): “radiation-related disorders of the skin and subcutaneous tissue (L55-L59)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • L21 — Seborrheic dermatitis[Excludes2](via L55.-): “radiation-related disorders of the skin and subcutaneous tissue (L55-L59)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • L22 — Diaper dermatitis[Excludes2](via L55.-): “radiation-related disorders of the skin and subcutaneous tissue (L55-L59)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • L23 — Allergic contact dermatitis[Excludes2](via L55.-): “radiation-related disorders of the skin and subcutaneous tissue (L55-L59)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • L24 — Irritant contact dermatitis[Excludes2](via L55.-): “radiation-related disorders of the skin and subcutaneous tissue (L55-L59)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • L25 — Unspecified contact dermatitis[Excludes2](via L55.-): “radiation-related disorders of the skin and subcutaneous tissue (L55-L59)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • L26 — Exfoliative dermatitis[Excludes2](via L55.-): “radiation-related disorders of the skin and subcutaneous tissue (L55-L59)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
  • and 7 more

Clinical classification (CCSR)

MS-DRG Grouper

MDC crossing

  • MDC 09 — Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast[MDC crossing]: “Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 7,376 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

  • Heat (effects), burn[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Sunburn[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "L55.9 — Sunburn, unspecified." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/l55.9-sunburn-unspecified

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Sunburn, unspecified

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to L55.9 in its code family, with their registry titles.

View all codes in the L55 family