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T23.11 ICD-10-CM Code: Burn of first degree of thumb (nail)

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Coding at a Glance

7th character
Required — see the character table on this page
Tabular directives
3 inclusion terms · 2 use-additional codes

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for T23.11 in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on T23.11 itself; “inherited from” names the category or block whose note applies here.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • burns and corrosions of first degree [erythema]
  • burns and corrosions of second degree [blisters][epidermal loss]
  • burns and corrosions of third degree [deep necrosis of underlying tissue] [full- thickness skin loss]

Source: inherited from T20-T25

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • external cause code to identify the source, place and intent of the burn (X00-X19, X75-X77, X96-X98, Y92) inherited from T23.1
  • Use additional code from category T31 or T32 to identify extent of body surface involved inherited from T20-T25

7th Character Guide

"The appropriate 7th character is to be added to each code from category T23"

  • A — initial encounter
  • D — subsequent encounter
  • S — sequela

How the encounter character is assigned. “Initial encounter” means the patient is receiving active treatment for the condition — it is not limited to the first visit, and a different or new provider giving active treatment still assigns it. “Subsequent encounter” covers care during the healing or recovery phase after active treatment. “Sequela” is for complications or conditions that arise as a direct result of the original condition.

ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19.a (paraphrased by MedCoder).

Variant codes in this family

T23.111A, T23.111D, T23.111S, T23.112A, T23.112D, T23.112S, T23.119A, T23.119D

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Coder workflow for T23.11

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

Before you code T23.11

  1. T23.11 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

    ReviewT23.111, T23.112, T23.119

    See the hierarchy · Guide: How to choose an ICD-10-CM code →

  2. A 7th character is required in this family. Confirm the documented encounter: initial (active treatment), subsequent (healing or recovery phase), or sequela. T23.11 is not valid without one. “Initial” means active treatment, not the first visit (Guidelines I.C.19.a).

    See the 7th Character Guide · Guide: 7th characters: initial, subsequent, sequela →

  3. Confirm the injury type, the anatomical site at the most specific level documented, laterality where the family codes it, and the encounter for the 7th character. Each injury is coded separately unless the classification provides a combination code, and a superficial injury is not coded when a more severe injury of the same site is documented. Injury chapter guidelines (Guidelines I.C.19.b, I.C.19.b.1).

    Guide: 7th characters: initial, subsequent, sequela →

Choose the right path

  1. Does the documentation support one of the more specific codes beneath T23.11?
    Yes → Select that code and continue the checks below on its own page.
    No → T23.11 cannot be reported as written; query for the specificity its subcategory needs.

    ReviewT23.111, T23.112, T23.119

  2. Is the encounter phase documented — active treatment, healing or recovery, or a sequela?
    Yes → Assign the matching 7th character; the variant codes are in the 7th Character Guide.
    No → The code is invalid without its 7th character — query for the missing element.

Consider T23.11. 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).
Anatomical site
At the most specific level the record states; a site the classification separates cannot be assumed from a procedure or a measurement.
Encounter type
Active treatment, healing or recovery phase, or sequela — the basis of the 7th character (Guidelines I.C.19.a).
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.
External cause, place and activity
For the external cause codes reported with the injury or poisoning, where documented (Guidelines I.C.20.a).

Official instructions as workflow

  • Use Additional Code — after identifying T23.11(2 notes)

    Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with T23.11 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

    ReviewY92, T31, T32

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

Coding decision scenarios

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

Documentation: The patient returns during the healing or recovery phase after active treatment of the same condition.

Coding question: Which 7th character applies?

Path: Review the official 7th-character definitions for this family in the 7th Character Guide.

Reason: “Initial encounter” means active treatment, not the first visit; care during recovery takes “subsequent encounter”, and a complication arising from the original condition takes “sequela” (Guidelines I.C.19.a).

Documentation: A condition the Use Additional Code note names is documented.

Coding question: Is a second code reported with T23.11?

Path: Review the Use Additional Code note and the code it names.

Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).

ReviewY92, T31, T32

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

Burn of first degree of thumb (nail) is a non-billable ICD-10-CM category code (T23.11). A more specific billable subcode must be selected for claims submission.

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

Verify Before Coding

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

Other codes that name T23.11 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 2 Excludes1 notes: T07 — Unspecified multiple injuries (via T23.-), T66 — Radiation sickness, unspecified (via T23.-).

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

Referenced by 122 Excludes2 notes: S00 — Superficial injury of head (via T23.-), S00-S09 — Injuries to the head (S00-S09) (via T23.-), S01 — Open wound of head (via T23.-), S02 — Fracture of skull and facial bones (via T23.-), S03 — Dislocation and sprain of joints and ligaments of head (via T23.-), S04 — Injury of cranial nerve (via T23.-), S05 — Injury of eye and orbit (via T23.-), S06 — Intracranial injury (via T23.-), S07 — Crushing injury of head (via T23.-), S08 — Avulsion and traumatic amputation of part of head (via T23.-), S09 — Other and unspecified injuries of head (via T23.-), S10 — Superficial injury of neck (via T23.-), S10-S19 — Injuries to the neck (S10-S19) (via T23.-), S11 — Open wound of neck (via T23.-), S12 — Fracture of cervical vertebra and other parts of neck (via T23.-), S13 — Dislocation and sprain of joints and ligaments at neck level (via T23.-), S14 — Injury of nerves and spinal cord at neck level (via T23.-), S15 — Injury of blood vessels at neck level (via T23.-), S16 — Injury of muscle, fascia and tendon at neck level (via T23.-), S17 — Crushing injury of neck (via T23.-), +102 more.

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

Contextual Map

Every relationship of T23.11 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 T23.11 with these 10 related codes in Claim Check

Hierarchy

Referenced by Excludes1 notes

Referenced by Excludes2 notes (122)

Nearest codes (40)

Change history

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

Common coding questions

Can T23.11 be billed directly?

No. T23.11 (Burn of first degree of thumb (nail)) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Does T23.11 require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category T23.

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

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Burn of first degree of thumb (nail)

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 T23.11 in its code family, with their registry titles.

View all codes in the T23 family