W21.9XXS ICD-10-CM Code: Striking against or struck by unspecified sports equipment, sequela
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Coding at a Glance
- 7th character
- Required — see the character table on this page
- Tabular directives
- 6 Excludes1
Coding instructions
Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for W21.9XXS in the official ICD-10-CM tabular list, quoted as published.
Notes without a marker are published on W21.9XXS itself; “inherited from” names the category or block whose note applies here.
Excludes1 — Not Coded Here
Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
- assault with sports equipment (Y08.0-) inherited from W21Compare W21.9XXS vs Y08.0 →
- striking against or struck by sports equipment with subsequent fall (W18.01) inherited from W21Compare W21.9XXS vs W18.01 →
- assault (X92-Y09) inherited from W20-W49Compare W21.9XXS vs X92 →
- contact or collision with animals or persons (W50-W64) inherited from W20-W49Compare W21.9XXS vs W50 →
- exposure to inanimate mechanical forces involving military or war operations (Y36.-, Y37.-) inherited from W20-W49Compare W21.9XXS vs Y36 →
- intentional self-harm (X71-X83) inherited from W20-W49Compare W21.9XXS vs X71 →
7th Character Guide
"The appropriate 7th character is to be added to each code from category W21"
- A — initial encounter
- D — subsequent encounter
- S — sequela (this page’s code)
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
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.
Code Overview
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
- Principal-diagnosis restriction. External cause of morbidity codes (V, W, X and Y) describe the circumstance that caused an injury, not the condition treated. The Medicare Code Editor rejects them as a principal diagnosis; sequence the injury or condition first and report this code as secondary.
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 W21.9XXS 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: W20 — Struck by thrown, projected or falling object (via W21.-), W50 — Accidental hit, strike, kick, twist, bite or scratch by another person (via W21.-).
These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.
Referenced by 1 Excludes2 note: W45 — Foreign body or object entering through skin (via W21.-).
These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.
Clinical classification (AHRQ CCSR):EXT030 — External cause codes: sequela.
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 (External cause codes: sequela).
Contextual Map
Every relationship of W21.9XXS 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 W21.9XXS with these 3 related codes in Claim Check
Hierarchy
- V00-Y99 — Chapter 20: External Causes of Morbidity (V00-Y99) (V00-Y99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W00-X58 — Other external causes of accidental injury[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W20-W49 — Exposure to inanimate mechanical forces[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
Referenced by Excludes1 notes
- W20 — Struck by thrown, projected or falling object[Excludes1](via W21.-): “struck by thrown sports equipment (W21.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- W50 — Accidental hit, strike, kick, twist, bite or scratch by another person[Excludes1](via W21.-): “struck by objects (W20-W22)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Referenced by Excludes2 notes
- W45 — Foreign body or object entering through skin[Excludes2](via W21.-): “struck by objects (W20-W22)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Clinical classification (CCSR)
- EXT030 — External cause codes: sequela[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
Nearest codes (40)
- W21 — Striking against or struck by sports equipment[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W21.211D — Struck by field hockey stick, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W21.211S — Struck by field hockey stick, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W21.22 — Struck by hockey puck[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W21.220 — Struck by ice hockey puck[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W21.220A — Struck by ice hockey puck, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W21.220D — Struck by ice hockey puck, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W21.220S — Struck by ice hockey puck, sequela[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
Does W21.9XXS require a 7th character?
Yes. The appropriate 7th character is to be added to each code from category W21.
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, 2015In the code set at ICD-10-CM adoptionStriking against or struck by unspecified sports equipment, sequela
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 W21.9XXS in its code family, with their registry titles.
- W21.81 — Striking against or struck by football helmet
- W21.81XA — Striking against or struck by football helmet, initial encounter
- W21.81XD — Striking against or struck by football helmet, subsequent encounter
- W21.81XS — Striking against or struck by football helmet, sequela
- W21.89 — Striking against or struck by other sports equipment
- W21.89XA — Striking against or struck by other sports equipment, initial encounter
- W21.89XD — Striking against or struck by other sports equipment, subsequent encounter
- W21.89XS — Striking against or struck by other sports equipment, sequela
- W21.9 — Striking against or struck by unspecified sports equipment
- W21.9XXA — Striking against or struck by unspecified sports equipment, initial encounter