L02.237 ICD-10-CM Code: Carbuncle of flank

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for L02.237 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on L02.237 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for L02.237

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

Before you code L02.237

1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with L02.237. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

   See the official tabular notes

Choose the right path

1. Does the documentation support a condition named in L02.237’s Excludes1 note?
   Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
   No → Continue.

   ReviewL08.82, P38

Consider L02.237. Then work the Use Additional Code note, and 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).

The conditions the Use Additional Code note names

Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Official instructions as workflow

• Excludes1 — check before selecting L02.237(2 notes)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with L02.237: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareL08.82, P38

  See the official tabular notes · Guidelines I.A.12.a

• Excludes2 — not part of L02.237(21 notes)

  Coding workflow: The conditions named in this note are not included in L02.237. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareN61.1, L02.31, N76.4, N48.2, N49, L02.4

  See the official tabular notes · Guidelines I.A.12.b

• Use Additional Code — after identifying L02.237(2 notes)

  Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with L02.237 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

  See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

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

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.

Indexed Clinical Terms (1)

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.

• Carbuncle, flank

Don’t confuse L02.237 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of L02.237 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• L08.82— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of non-newborn omphalitis moves the case to L08.82; the two are not reported together unless documented as unrelated.

  Full comparison: L02.237 vs L08.82 →

• P38— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of omphalitis of newborn moves the case to P38; the two are not reported together unless documented as unrelated.

  Full comparison: L02.237 vs P38 →

• L02.239— Specificity relationship (Review)

  Overlapping diagnoses in the same category.

  Overlapping codes in the same category — the documentation decides which is the more specific fit.

  What moves you there: A record that documents no more than “Carbuncle of trunk, unspecified” takes L02.239; specificity in the record moves it back here.

  Full comparison: L02.237 vs L02.239 →

• N61.1— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of abscess of breast adds N61.1; it is not part of this code and both may be reported when both are documented.

  Full comparison: L02.237 vs N61.1 →

• L02.31— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of abscess of buttocks adds L02.31; it is not part of this code and both may be reported when both are documented.

  Full comparison: L02.237 vs L02.31 →

• N76.4— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of abscess of female external genital organs adds N76.4; it is not part of this code and both may be reported when both are documented.

  Full comparison: L02.237 vs N76.4 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

1. 2 Use Additional Code instructions — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
2. 2 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes
3. 21 Excludes2 entries — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

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 L02.237 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 Excludes2 notes: L89 — Pressure ulcer (via L02.-), L97 — Non-pressure chronic ulcer of lower limb, not elsewhere classified (via L02.-), L98.4 — Non-pressure chronic ulcer of skin, not elsewhere classified (via L02.-), L98.A — Non-pressure chronic ulcer of upper limb, not elsewhere classified (via L02.-).

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

Referenced by 1 Use Additional Code instruction: T65.84 — Toxic effect of xylazine (via L02.-).

These codes instruct coders to additionally report this code when it applies.

Related Codes

Same Index main term, other category

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

A22.0 — Cutaneous anthrax (malignant), J34.0 — Abscess, furuncle and carbuncle of nose (nose), K61.0 — Anal abscess (anus), N34.0 — Urethral abscess (urethra), N48.21 — Abscess of corpus cavernosum and penis (penis), N49.0 — Inflammatory disorders of seminal vesicle (seminal vesicle), N61.1 — Abscess of the breast and nipple (breast), N76.4 — Abscess of vulva (vulva)

Contextual Map

Every relationship of L02.237 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 L02.237 with these 5 related codes in Claim Check

Hierarchy

• L00-L99 — Chapter 12: Diseases of the Skin and Subcutaneous Tissue (L00-L99) (L00-L99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• L00-L08 — Infections of the skin and subcutaneous tissue[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes2 notes

• L89 — Pressure ulcer[Excludes2](via L02.-): “skin infections (L00-L08)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• L97 — Non-pressure chronic ulcer of lower limb, not elsewhere classified[Excludes2](via L02.-): “skin infections (L00-L08)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• L98.4 — Non-pressure chronic ulcer of skin, not elsewhere classified[Excludes2](via L02.-): “skin infections (L00-L08)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• L98.A — Non-pressure chronic ulcer of upper limb, not elsewhere classified[Excludes2](via L02.-): “skin infections (L00-L08)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Use Additional Code instructions

• T65.84 — Toxic effect of xylazine[Use Additional Code](via L02.-): “cutaneous abscess, furuncle and carbuncle (L02.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Index entries

• Carbuncle, flank[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (40)

• L02 — Cutaneous abscess, furuncle and carbuncle[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• L02.215 — Cutaneous abscess of perineum[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• L02.216 — Cutaneous abscess of umbilicus[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• L02.217 — Cutaneous abscess of flank[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• L02.219 — Cutaneous abscess of trunk, unspecified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• L02.22 — Furuncle of trunk[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• L02.221 — Furuncle of abdominal wall[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• L02.222 — Furuncle of back [any part, except buttock and flank][Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 32 more

Change history

• FY2027 — Will be added to the code set[Change history]— CMS release files (code change ledger) · icd10cm-fy2027

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

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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to L02.237 in its code family, with their registry titles.

• L02.232 — Carbuncle of back [any part, except buttock and flank]
• L02.233 — Carbuncle of chest wall
• L02.234 — Carbuncle of groin
• L02.235 — Carbuncle of perineum
• L02.236 — Carbuncle of umbilicus
• L02.239 — Carbuncle of trunk, unspecified
• L02.3 — Cutaneous abscess, furuncle and carbuncle of buttock
• L02.31 — Cutaneous abscess of buttock
• L02.32 — Furuncle of buttock
• L02.33 — Carbuncle of buttock

View all codes in the L02 family