2026 ICD-10-CM Diagnosis Code F43.0Acute stress reaction

ICD-10-CM Codes›F01–F99›F40-F48›F43

ICD-10-CM F43.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

F43.0 is a billable ICD-10-CM diagnosis code for acute stress reaction. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Trauma- and stressor-related disorders.

Code Identity

ICD-10-CM Code
F43.0
Billable Status
Yes — Valid for Submission
Code Describes
Acute stress reaction
Short Description
Acute stress reaction
Same as the full description in the CMS dataset.
Parent Code
F43
Reaction to severe stress, and adjustment disorders

Code Classification

ChapterF01–F99Mental and behavioural disorders
SectionF40-F48Anxiety, dissociative, stress-related, somatoform and other nonpsychotic mental disorders
CategoryF43Reaction to severe stress, and adjustment disorders
This CodeF43.0Acute stress reaction

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute fugue state due to acute stress reaction
  • Acute panic state due to acute stress reaction
  • Acute stress disorder
  • Acute stupor state due to acute stress reaction
  • Clouded consciousness
  • Combat fatigue
  • Crisis
  • Exhaustion delirium
  • Psychogenic fugue
  • Psychogenic fugue co-occurrent and due to stress reaction
  • Shell shock
  • Situational crisis
  • Stress and adjustment reaction
  • Stupor

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Acute crisis reaction
  • Acute reaction to stress
  • Combat and operational stress reaction
  • Combat fatigue
  • Crisis state
  • Psychic shock

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Battle exhaustion
    • Combat fatigue
    • Crisis
      • acute reaction
    • Crisis
      • emotional
        • acute reaction to stress
    • Crisis
      • state (acute reaction)
    • Delirium, delirious(acute or subacute) (not alcohol- or drug-induced)
      • exhaustion
    • Disorder(of)
      • acute
        • stress
    • Disorder(of)
      • dissociative
        • brief reactive
    • Disorder(of)
      • stress
        • acute
    • Disturbance(s)
      • situational (transient)
        • acute
    • Exhaustion, exhaustive(physical NEC)
      • battle
    • Exhaustion, exhaustive(physical NEC)
      • delirium
    • Exhaustion, exhaustive(physical NEC)
      • psychosis
    • Fatigue
      • combat
    • Fugue
      • reaction to exceptional stress (transient)
    • Panic(attack) (state)
      • reaction to exceptional stress (transient)
    • Psychosis, psychotic
      • exhaustive
    • Reaction
      • combat and operational stress
    • Reaction
      • crisis, acute
    • Reaction
      • stress (severe)
        • acute (agitation) ("daze") (disorientation) (disturbance of consciousness) (flight reaction) (fugue)
    • Shellshock(current)
    • Shock
      • psychic
    • Situational
      • disturbance (transient)
        • acute
    • Situational
      • reaction
        • acute
    • State(of)
      • agitated
        • acute reaction to stress
    • State(of)
      • crisis
    • Stupor(catatonic)
      • reaction to exceptional stress (transient)

Clinical ClassificationClinical

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

CCSR MBD007
Trauma- and stressor-related disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Hepatic Encephalopathy

    a syndrome characterized by central nervous system dysfunction in association with liver failure, including portal-systemic shunts. clinical features include lethargy and confusion (frequently progressing to coma); asterixis; nystagmus, pathologic; brisk oculovestibular reflexes; decorticate and decerebrate posturing; muscle spasticity; and bilateral extensor plantar reflexes (see reflex, babinski). electroencephalography may demonstrate triphasic waves. (from adams et al., principles of neurology, 6th ed, pp1117-20; plum & posner, diagnosis of stupor and coma, 3rd ed, p222-5)

  • Stupor

    a state of reduced sensibility and response to stimuli which is distinguished from coma in that the person can be aroused by vigorous and repeated stimulation. the person is still conscious and can make voluntary movements. it can be induced by central nervous system agents. the word derives from latin stupere and is related to stunned, stupid, dazed or lethargy.

  • Acute Stress Disorder

    an anxiety disorder precipitated by an experience of intense fear or horror while exposed to a traumatic (especially life-threatening) event. the disorder is characterized by dissociative symptoms; vivid recollections of the traumatic event; avoidance of stimuli associated with the traumatic event; and a constant state of hyperarousal for no more than one month.

Patient EducationClinical

Stress

Stress is how your brain and body respond to a challenge or demand. When you are stressed, your body releases certain hormones. Hormones are chemicals that travel in your bloodstream and control how different parts of your body work. The hormones that are released when you are stressed make you alert and ready to act.

The full article covers:

  • What is stress?
  • What causes long-term stress?
  • How can long term-stress harm my health?
  • How can I manage long-term stress?
  • When should I ask my health care provider for help with stress?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert F43.0 to ICD-9-CMHistory

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

ICD-9-CM
308.9 Acute stress react NOS
Approximate The match is approximate rather than exact.

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 F43.0Overview

Is F43.0 (Reaction to severe stress, and adjustment disorders) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report acute stress reaction on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of F43.0?

Under the General Equivalence Mappings, acute stress reaction converts to ICD-9-CM 308.9 (acute stress react NOS). 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.