W20 ICD-10-CM Code: Struck by thrown, projected or falling object
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 — characters A · D · S
- Tabular directives
- 9 Excludes1 · 3 code-first instructions
Coding instructions
Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for W20 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 W20 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).
- falling object in machinery accident (W24, W28-W31) Compare W20 vs W24 →
- falling object in transport accident (V01-V99) Compare W20 vs V01 →
- object set in motion by explosion (W35-W40) Compare W20 vs W35 →
- object set in motion by firearm (W32-W34) Compare W20 vs W32 →
- struck by thrown sports equipment (W21.-) Compare W20 vs W21 →
- assault (X92-Y09) inherited from W20-W49Compare W20 vs X92 →
- contact or collision with animals or persons (W50-W64) inherited from W20-W49Compare W20 vs W50 →
- exposure to inanimate mechanical forces involving military or war operations (Y36.-, Y37.-) inherited from W20-W49Compare W20 vs Y36 →
- intentional self-harm (X71-X83) inherited from W20-W49Compare W20 vs X71 →
Code First
Underlying conditions that must be sequenced before this code.
- any associated:
- cataclysm (X34-X39)
- lightning strike (T75.00)
7th Character Guide
"The appropriate 7th character is to be added to each code from category W20"
- 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
W20-W49, W20.0XXA, W20.0XXD, W20.0XXS, W20.1XXA, W20.1XXD, W20.1XXS, W20.8XXA
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 W20
MedCoder structured workflow — derived from this code’s own official record
Before you code W20
- W20 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).
See the relationships section · Guide: How to choose an ICD-10-CM code →
- A 7th character is required in this family. Confirm the documented encounter: initial (active treatment), subsequent (healing or recovery phase), or sequela. W20 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 →
- An external cause code is reported in addition to the code for the injury or condition, never as the principal or first-listed diagnosis. Confirm the cause, intent, place of occurrence, activity and status where the record documents them, and assign the 7th character that matches the injury code. External cause coding guidelines (Guidelines I.C.20.a).
- Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with W20. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).
Choose the right path
- Does the documentation support one of the more specific codes beneath W20?
Yes → Select that code and continue the checks below on its own page.
No → W20 cannot be reported as written; query for the specificity its subcategory needs. - Does the documentation support a condition named in W20’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. - Is the underlying (etiologic) condition the Code First note names documented?
Yes → Sequence the underlying condition first, then W20.
No → Continue; do not add an underlying condition the record does not document.ReviewT75.00
- 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 W20. 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).
- Encounter type
- Active treatment, healing or recovery phase, or sequela — the basis of the 7th character (Guidelines I.C.19.a).
- The underlying (etiologic) condition
- Named in the Code First note; sequenced before this code when documented (Guidelines I.A.13).
Official instructions as workflow
Excludes1 — check before selecting W20(9 notes)
Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with W20: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.
See the official tabular notes · Guidelines I.A.12.a
Code First — sequencing check(3 notes)
Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before W20. Do not add an underlying condition the record does not document.
ReviewT75.00
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: Both the condition W20 describes and a condition named in its Excludes1 note are documented for the same encounter.
Coding question: Can both codes be reported?
Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.
Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).
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: The underlying condition the Code First note names is documented alongside this condition.
Coding question: How are the two sequenced?
Path: Review the Code First note.
Reason: The underlying condition is sequenced first and the manifestation follows (Guidelines I.A.13).
ReviewT75.00
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
MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.
Decision Points
The directives on this code's own record, as a pre-claim checklist.
- 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
- Sequencing: 3 Code First instructions — the underlying condition is sequenced before this code when present. See the Code First notes
- 9 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 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
- Not billable as written — a more specific code is required: W20.0XXA, W20.0XXD, W20.0XXS, W20.1XXA, W20.1XXD.
- Requires a 7th character. "The appropriate 7th character is to be added to each code from category W20" Options: W20-W49, W20.0XXA, W20.0XXD, W20.0XXS, W20.1XXA, W20.1XXD
- 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
MedCoder structured relationships — computed from published CMS and AHRQ datasets
Other codes that name W20 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: W13.9 — Fall from, out of or through building, not otherwise specified, W22.8 — Striking against or struck by other objects, W23 — Caught, crushed, jammed or pinched in or between objects, W50 — Accidental hit, strike, kick, twist, bite or scratch by another person.
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.
These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.
Contextual Map
Every relationship of W20 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 W20 with these 20 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
Excludes1 (44)
- W21 — Striking against or struck by sports equipment[Excludes1]: “struck by thrown sports equipment (W21.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- W24 — Contact with lifting and transmission devices, not elsewhere classified[Excludes1]: “falling object in machinery accident (W24, W28-W31)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- W28 — Contact with powered lawn mower[Excludes1]: “falling object in machinery accident (W24, W28-W31)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- W29 — Contact with other powered hand tools and household machinery[Excludes1]: “falling object in machinery accident (W24, W28-W31)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- W30 — Contact with agricultural machinery[Excludes1]: “falling object in machinery accident (W24, W28-W31)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- W31 — Contact with other and unspecified machinery[Excludes1]: “falling object in machinery accident (W24, W28-W31)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- W32 — Accidental handgun discharge and malfunction[Excludes1]: “object set in motion by firearm (W32-W34)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- W33 — Accidental rifle, shotgun and larger firearm discharge and malfunction[Excludes1]: “object set in motion by firearm (W32-W34)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- and 36 more
Code First
- T75.00 — Unspecified effects of lightning[Code First]: “lightning strike (T75.00)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- X34 — Earthquake[Code First]: “cataclysm (X34-X39)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- X35 — Volcanic eruption[Code First]: “cataclysm (X34-X39)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- X36 — Avalanche, landslide and other earth movements[Code First]: “cataclysm (X34-X39)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- X37 — Cataclysmic storm[Code First]: “cataclysm (X34-X39)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- X38 — Flood[Code First]: “cataclysm (X34-X39)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- X39 — Exposure to other forces of nature[Code First]: “cataclysm (X34-X39)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Referenced by Excludes1 notes
- W13.9 — Fall from, out of or through building, not otherwise specified[Excludes1]: “collapse of a building or structure (W20.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- W22.8 — Striking against or struck by other objects[Excludes1]: “struck by thrown, projected or falling object (W20.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- W23 — Caught, crushed, jammed or pinched in or between objects[Excludes1]: “injury caused by struck by thrown, projected or falling object (W20.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- W50 — Accidental hit, strike, kick, twist, bite or scratch by another person[Excludes1]: “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]: “struck by objects (W20-W22)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Nearest codes (12)
- W20.0 — Struck by falling object in cave-in[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W20.0XXA — Struck by falling object in cave-in, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W20.0XXD — Struck by falling object in cave-in, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W20.0XXS — Struck by falling object in cave-in, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W20.1 — Struck by object due to collapse of building[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W20.1XXA — Struck by object due to collapse of building, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W20.1XXD — Struck by object due to collapse of building, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W20.1XXS — Struck by object due to collapse of building, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- and 4 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
Can W20 be billed directly?
No. W20 (Struck by thrown, projected or falling object) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.
Does W20 require a 7th character?
Yes. The appropriate 7th character is to be added to each code from category W20; A: initial encounter; D: subsequent encounter; S: sequela.
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
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. "W20 — Struck by thrown, projected or falling object." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/w20-struck-by-thrown-projected-or-falling-object
Change history
- FY2016 — October 1, 2015In the code set at ICD-10-CM adoptionStruck by thrown, projected or falling object
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 W20 in its code family, with their registry titles.
- W20.0 — Struck by falling object in cave-in
- W20.0XXA — Struck by falling object in cave-in, initial encounter
- W20.0XXD — Struck by falling object in cave-in, subsequent encounter
- W20.0XXS — Struck by falling object in cave-in, sequela
- W20.1 — Struck by object due to collapse of building
- W20.1XXA — Struck by object due to collapse of building, initial encounter
- W20.1XXD — Struck by object due to collapse of building, subsequent encounter
- W20.1XXS — Struck by object due to collapse of building, sequela
- W20.8 — Other cause of strike by thrown, projected or falling object
- W20.8XXA — Other cause of strike by thrown, projected or falling object, initial encounter
- W20.8XXD — Other cause of strike by thrown, projected or falling object, subsequent encounter
- W20.8XXS — Other cause of strike by thrown, projected or falling object, sequela