2027 ICD-10-CM Diagnosis Code Y09Assault by unspecified means

ICD-10-CM Codes›V01–Y99›X92-Y09›Y09

ICD-10-CM Y09
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

Y09 is a billable ICD-10-CM diagnosis code for assault by unspecified means. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under External cause codes: intent of injury, assault; and External cause codes: unspecified mechanism.

Code Identity

ICD-10-CM Code
Y09
Billable Status
Yes — Valid for Submission
Code Describes
Assault by unspecified means
Short Description
Assault by unspecified means
Same as the full description in the CMS dataset.
Chapter
X92-Y09
Assault

Code Classification

ChapterV01–Y99External causes of morbidity and mortality
SectionX92-Y09Assault
CategoryY09Assault by unspecified means
This CodeY09Assault by unspecified means

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Assault
  • Assault and battery
  • Assault by person
  • Battery
  • Death due to assault AND battery
  • Euthanasia
  • Exposure to attack by other person
  • First degree murder
  • Fratricide
  • Gangland style homicide
  • Homicide
  • Homicide and assault by fight, brawl and rape
  • Homicide attempt
  • Homicide by overkill
  • Infanticide
  • Justifiable homicide
  • Killing
  • Late effect due to homicide attempt
  • Late effects of assault
  • Manslaughter
  • Matricide
  • Murder
  • Murder by hired killer
  • Murder of acquaintance
  • Murder of friend
  • Murder of relative
  • Murder of spouse
  • Murder of stranger
  • Non-judicial execution
  • Patricide
  • Second degree murder
  • Serial killing
  • Sororicide
  • Traumatic injury due to assault
  • Undetermined manner of death
  • Undetermined manner of death, homicide suspected
  • Unlawful killing

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Y09: its own notes plus those printed at block X92-Y09 and Chapter 20. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block X92-Y09 Assault applies to 202 codes
  • homicide
  • injuries inflicted by another person with intent to injure or kill, by any means

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Assassination (attempted) NOS
  • Homicide (attempted) NOS
  • Manslaughter (attempted) NOS
  • Murder (attempted) NOS

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Block X92-Y09 Assault applies to 202 codes
  • injuries due to legal intervention (Y35.-)
  • injuries due to operations of war (Y36.-)
  • injuries due to terrorism (Y38.-)

Notes

General instructions on how these codes are used.

From Chapter 20 (V00-Y99) External causes of morbidity and mortality applies to 7,461 codes
  • This chapter permits the classification of environmental events and circumstances as the cause of injury, and other adverse effects. Where a code from this section is applicable, it is intended that it shall be used secondary to a code from another chapter of the Classification indicating the nature of the condition. Most often, the condition will be classifiable to Chapter 19, Injury, poisoning and certain other consequences of external causes (S00-T88). Other conditions that may be stated to be due to external causes are classified in Chapters I to XVIII. For these conditions, codes from Chapter 20 should be used to provide additional information as to the cause of the condition.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index; each main term links to its index entry.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR EXT022
External cause codes: intent of injury, assault
Default principal diagnosis: inpatient No · outpatient No
CCSR EXT019
External cause codes: unspecified mechanism
Default principal diagnosis: inpatient No · outpatient No

Convert Y09 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
E968.9 Assault NOS
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About Y09Overview

What is the ICD-10 code for assault by unspecified means?

The ICD-10-CM code for assault by unspecified means is Y09. It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is Y09 (Assault by unspecified means) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report assault by unspecified means on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Can Y09 be reported with a code from Y35?

Not as a rule. The Excludes1 note at block X92-Y09, which applies to Y09, lists "injuries due to legal intervention (Y35.-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is the ICD-9 equivalent of Y09?

Under the General Equivalence Mappings, assault by unspecified means converts to ICD-9-CM E968.9 (assault NOS). The mapping is a direct match.