T20.012A ICD-10-CM Code: Burn of unspecified degree of left ear [any part, except ear drum], initial encounter

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for T20.012A in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on T20.012A itself; “inherited from” names the category or block whose note applies here.

7th Character Guide

"The appropriate 7th character is to be added to each code from category T20"

• A — initial encounter (this page’s code)
• 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

T20.012A, T20.012D, T20.012S

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 T20.012A

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

Before you code T20.012A

1. Unspecified does not mean incorrect. When the record gives no greater specificity, T20.012A 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).

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

2. A 7th character is required in this family. Confirm the documented encounter: initial (active treatment), subsequent (healing or recovery phase), or sequela. This page’s code carries “A”. “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. Laterality is coded in this family. Confirm the side documented — right, left, or bilateral — and select the matching code (this page’s code: left). The unspecified-side code applies only when the record states no side. Laterality is assigned from the documented side; where a bilateral code exists and both sides are documented, it is used instead of two unilateral codes (Guidelines I.B.13).

   ReviewT20.011A · right, T20.019A · unspecified

   Guide: Laterality coding →

4. 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 record document the detail a more specific sibling code needs?
   Yes → Review the specific siblings in this subcategory.
   No → Continue — T20.012A is appropriate when the documentation goes no further.
2. Is the side documented?
   Yes → Select the code for the documented side (or the bilateral code when both sides are documented and one exists).
   No → Use the unspecified-side code only when the record states no side; a query is the alternative.

   ReviewT20.011A · right, T20.019A · unspecified

3. 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 T20.012A. 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.

Laterality

Right, left or bilateral as documented; unspecified only when the record states no side (Guidelines I.B.13).

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).

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.

Official instructions as workflow

• Excludes2 — not part of T20.012A(4 notes)

  Coding workflow: The conditions named in this note are not included in T20.012A. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareT28.41, T28.91, T26, T28.0

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

• Use Additional Code — after identifying T20.012A(2 notes)

  Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with T20.012A 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

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.

Official Coding Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Official source data — quoted verbatim from the CMS/NCHS Official Guidelines

Verbatim excerpts from the ICD-10-CM Official Guidelines for Coding and Reporting (CMS/NCHS) that govern this code.

Don’t confuse T20.012A with…

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

The codes most likely to be picked instead of T20.012A — 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.

• T20.011A— Laterality relationship (Review)

  Same condition; these differ only in which side is documented.

  The same condition on the other side; the documented side decides, and a bilateral code, where one exists, replaces the pair when both sides are documented.

  What moves you there: A documented right side moves the case to T20.011A.

  Full comparison: T20.012A vs T20.011A →

• T20.019A— Laterality relationship (Review)

  Same condition; these differ only in which side is documented.

  The same condition on the other side; the documented side decides, and a bilateral code, where one exists, replaces the pair when both sides are documented.

  What moves you there: A record that states no side takes T20.019A; a documented side moves it back to a sided code.

  Full comparison: T20.012A vs T20.019A →

• T20.012D— Encounter relationship (Review)

  Same underlying diagnosis, different encounter phase.

  The same diagnosis at a different phase of care; one encounter takes one 7th character.

  What moves you there: Documentation of a subsequent encounter moves the case to T20.012D.

  Full comparison: T20.012A vs T20.012D →

• T20.012S— Encounter relationship (Review)

  Same underlying diagnosis, different encounter phase.

  The same diagnosis at a different phase of care; one encounter takes one 7th character.

  What moves you there: Documentation of a sequela moves the case to T20.012S.

  Full comparison: T20.012A vs T20.012S →

• T28.41— 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 burn of ear drum adds T28.41; it is not part of this code and both may be reported when both are documented.

  Full comparison: T20.012A vs T28.41 →

• T28.91— 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 burn and corrosion of ear drum adds T28.91; it is not part of this code and both may be reported when both are documented.

  Full comparison: T20.012A vs T28.91 →

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. A 7th character applies in this family. Confirm the documented encounter matches the character assigned. See the official 7th-character definitions and this code’s variants
2. Laterality is coded in this family. Confirm the documented side matches the code — the opposite-side siblings are in the relationships section. See the opposite-side sibling codes
3. 2 Use Additional Code instructions — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
4. 4 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 T20.012A 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 T20.-), T66 — Radiation sickness, unspecified (via T20.-).

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

Referenced by 121 Excludes2 notes: S00 — Superficial injury of head (via T20.-), S00-S09 — Injuries to the head (S00-S09) (via T20.-), S01 — Open wound of head (via T20.-), S02 — Fracture of skull and facial bones (via T20.-), S03 — Dislocation and sprain of joints and ligaments of head (via T20.-), S04 — Injury of cranial nerve (via T20.-), S05 — Injury of eye and orbit (via T20.-), S06 — Intracranial injury (via T20.-), S07 — Crushing injury of head (via T20.-), S08 — Avulsion and traumatic amputation of part of head (via T20.-), S09 — Other and unspecified injuries of head (via T20.-), S10 — Superficial injury of neck (via T20.-), S10-S19 — Injuries to the neck (S10-S19) (via T20.-), S11 — Open wound of neck (via T20.-), S12 — Fracture of cervical vertebra and other parts of neck (via T20.-), S13 — Dislocation and sprain of joints and ligaments at neck level (via T20.-), S14 — Injury of nerves and spinal cord at neck level (via T20.-), S15 — Injury of blood vessels at neck level (via T20.-), S16 — Injury of muscle, fascia and tendon at neck level (via T20.-), S17 — Crushing injury of neck (via T20.-), +101 more.

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.

Not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity.

Named in the grouper logic of 1 MS-DRG: DRG 935 (MDC 22).

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

Clinical classification (AHRQ CCSR):INJ019 — Burn and corrosion, initial encounter (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 condition, opposite side

Same category and title, differing only in which side of the body is affected.

T20.011A — Burn of unspecified degree of right ear [any part, except ear drum], initial encounter (right)Compare T20.012A vs T20.011A →, T20.019A — Burn of unspecified degree of unspecified ear [any part, except ear drum], initial encounter (unspecified)Compare T20.012A vs T20.019A →

Same injury, other encounter phase

Same injury, coded at a different phase of treatment via the 7th character.

T20.012D — Burn of unspecified degree of left ear [any part, except ear drum], subsequent encounterCompare T20.012A vs T20.012D →, T20.012S — Burn of unspecified degree of left ear [any part, except ear drum], sequelaCompare T20.012A vs T20.012S →

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Burn and corrosion, initial encounter).

+935 more

Contextual Map

Every relationship of T20.012A 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 T20.012A with these 10 related codes in Claim Check

Hierarchy

• S00-T88 — Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) (S00-T88)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T20-T25 — Burns and corrosions of external body surface, specified by site[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• T07 — Unspecified multiple injuries[Excludes1](via T20.-): “burns and corrosions (T20-T32)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T66 — Radiation sickness, unspecified[Excludes1](via T20.-): “burns (T20-T31)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes2 notes (121)

• S00 — Superficial injury of head[Excludes2](via T20.-): “burns and corrosions (T20-T32)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• S00-S09 — Injuries to the head (S00-S09)[Excludes2](via T20.-): “burns and corrosions (T20-T32)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• S01 — Open wound of head[Excludes2](via T20.-): “burns and corrosions (T20-T32)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• S02 — Fracture of skull and facial bones[Excludes2](via T20.-): “burns and corrosions (T20-T32)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• S03 — Dislocation and sprain of joints and ligaments of head[Excludes2](via T20.-): “burns and corrosions (T20-T32)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• S04 — Injury of cranial nerve[Excludes2](via T20.-): “burns and corrosions (T20-T32)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• S05 — Injury of eye and orbit[Excludes2](via T20.-): “burns and corrosions (T20-T32)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• S06 — Intracranial injury[Excludes2](via T20.-): “burns and corrosions (T20-T32)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• and 113 more

Clinical classification (CCSR)

• INJ019 — Burn and corrosion, initial encounter[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• DRG 935 — NON-EXTENSIVE BURNS[MS-DRG]: “NON-EXTENSIVE BURNS (MDC 22)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 22 — Burns[MDC crossing]: “Burns — 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. 377 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Nearest codes (40)

• T20 — Burn and corrosion of head, face, and neck[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T20.0 — Burn of unspecified degree of head, face, and neck[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T20.00 — Burn of unspecified degree of head, face, and neck, unspecified site[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T20.00XA — Burn of unspecified degree of head, face, and neck, unspecified site, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T20.00XD — Burn of unspecified degree of head, face, and neck, unspecified site, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T20.00XS — Burn of unspecified degree of head, face, and neck, unspecified site, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T20.01 — Burn of unspecified degree of ear [any part, except ear drum][Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T20.011 — Burn of unspecified degree of right ear [any part, except ear drum][Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 32 more

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

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

Coding guidelines Official source data

ICD-10-CM Official Guidelines for Coding and Reporting (FY2026), quoted by section 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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T20.012A in its code family, with their registry titles.

• T20.011 — Burn of unspecified degree of right ear [any part, except ear drum]
• T20.011A — Burn of unspecified degree of right ear [any part, except ear drum], initial encounter
• T20.011D — Burn of unspecified degree of right ear [any part, except ear drum], subsequent encounter
• T20.011S — Burn of unspecified degree of right ear [any part, except ear drum], sequela
• T20.012 — Burn of unspecified degree of left ear [any part, except ear drum]
• T20.012D — Burn of unspecified degree of left ear [any part, except ear drum], subsequent encounter
• T20.012S — Burn of unspecified degree of left ear [any part, except ear drum], sequela
• T20.019 — Burn of unspecified degree of unspecified ear [any part, except ear drum]
• T20.019A — Burn of unspecified degree of unspecified ear [any part, except ear drum], initial encounter
• T20.019D — Burn of unspecified degree of unspecified ear [any part, except ear drum], subsequent encounter

View all codes in the T20 family