2026 ICD-10-CM Diagnosis Code T71.164AAsphyxiation due to hanging, undetermined, initial encounter

ICD-10-CM Codes›S00–T88›T66-T78›T71

ICD-10-CM T71.164A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T71.164A is a billable ICD-10-CM diagnosis code for asphyxiation due to hanging, undetermined, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. Coders also document this condition as asphyxia by strangulation. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Effect of other external causes, initial encounter; External cause codes: intent of injury, undetermined; and External cause codes: suffocation/inhalation; initial encounter.

Code Identity

ICD-10-CM Code
T71.164A
Billable Status
Yes — Valid for Submission
Code Describes
Asphyxiation due to hanging, undetermined, initial encounter
Short Description
Asphyxiation due to hanging, undetermined, initial encounter
Same as the full description in the CMS dataset.
Parent Code
T71.164
Asphyxiation due to hanging, undetermined

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT66-T78Other and unspecified effects of external causes
CategoryT71Asphyxiation
This CodeT71.164AAsphyxiation due to hanging, undetermined, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Asphyxia by strangulation
  • Asphyxia by strangulation by noose
  • Asphyxiation by hanging

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Asphyxiation (T71). Use the following options for the applicable episode of care:

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

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

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

CCSR INJ021
Effect of other external causes, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR EXT023
External cause codes: intent of injury, undetermined
Default principal diagnosis: inpatient No · outpatient No
CCSR EXT017
External cause codes: suffocation/inhalation; initial encounter
Default principal diagnosis: inpatient No · outpatient No

Convert T71.164A to ICD-9-CMHistory

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

ICD-9-CM
994.7 Asphyxiation/strangulat
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
E983.0 Undetermin circ-hanging
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T71.164AOverview

Is T71.164A (Asphyxiation due to hanging, undetermined) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report asphyxiation due to hanging, undetermined, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T71.164A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for asphyxiation due to hanging, undetermined, such as an emergency visit or first evaluation.

What MS-DRG does T71.164A group to?

When asphyxiation due to hanging, undetermined, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of T71.164A?

Under the General Equivalence Mappings, asphyxiation due to hanging, undetermined, initial encounter converts to ICD-9-CM 994.7 (asphyxiation/strangulat) and E983.0 (undetermin circ-hanging). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.