ICD-10-CM Tabular Index · Chapter 5 · FY 2026 F43

Reaction to severe stress, and adjustment disorders (F43) ICD-10-CM

The F43 code range covers reaction to severe stress, and adjustment disorders with 18 ICD-10-CM diagnosis codes. 14 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.

✓ Built from the official CMS FY 2026 datasetEffective Oct 1, 2025 – Sep 30, 2026
18
Diagnosis Codes
14
Billable Codes
F43
Code Range
F40–F48
Parent Section
ICD-10-CM

Codes in the F43 Range 18 codes · 14 billable

18 of 18 shown
  • F43 Reaction to severe stress, and adjustment disordersNon-billable
  • F43.0 Acute stress reaction
  • F43.1 Post-traumatic stress disorder (PTSD)Non-billable
  • F43.10 Post-traumatic stress disorder, unspecified
  • F43.11 Post-traumatic stress disorder, acute
  • F43.12 Post-traumatic stress disorder, chronic
  • F43.2 Adjustment disordersNon-billable
  • F43.20 Adjustment disorder, unspecified
  • F43.21 Adjustment disorder with depressed mood
  • F43.22 Adjustment disorder with anxiety
  • F43.23 Adjustment disorder with mixed anxiety and depressed mood
  • F43.24 Adjustment disorder with disturbance of conduct
  • F43.25 Adjustment disorder with mixed disturbance of emotions and conduct
  • F43.29 Adjustment disorder with other symptoms
  • F43.8 Other reactions to severe stressNon-billable
  • F43.81 Prolonged grief disorder
  • F43.89 Other reactions to severe stress
  • F43.9 Reaction to severe stress, unspecified

Clinical Terms in This Code Range

Definitions from the National Library of Medicine for conditions coded in the F43 range.

Adjustment Disorders

Maladaptive reactions to identifiable psychosocial stressors occurring within a short time after onset of the stressor. They are manifested by either impairment in social or occupational functioning or by symptoms (depression, anxiety, etc.) that are in excess of a normal and expected reaction to the stressor.

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)

Prolonged Grief Disorder

Severe and disabling grief reactions that do not remit in the 12 months after the death of a significant other. The core of the diagnosis includes persistent yearning or missing the deceased, and preoccupation with the circumstance of the death. (Carmassi, Clinical Handbook of Bereavement and Grief Reactions, 2018)

Psychomotor Agitation

A feeling of restlessness associated with increased motor activity. This may occur as a manifestation of nervous system drug toxicity or other conditions.

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.

About the F43 Code Range

ICD-10 code F43 covers reactions to severe stress and adjustment disorders, which include acute stress reactions, post-traumatic stress disorder (PTSD), and various adjustment disorders. These codes are used to classify conditions arising after exposure to significant stress or trauma.

This section includes the F43.0 code for acute stress reactions, also known as acute panic state or shell shock, highlighting sudden responses to extreme stress. The PTSD category, including F43.1 and its specifiers (F43.10 to F43.12), captures disorders like chronic or acute PTSD, sometimes called complex posttraumatic stress disorder or combat fatigue. Adjustment disorders, from F43.2 and its subcodes, address difficulty coping with life changes or stress, presenting with symptoms such as anxiety, depressed mood, or conduct disturbance. Variants like anticipatory grief or difficulty adapting after personal crisis also fall under these codes. Other codes (F43.8, F43.81, F43.89, and F43.9) describe less common or unspecified stress reactions including prolonged grief disorder and stress-induced muscle tension. This section enables precise coding for trauma- and stressor-related mental health conditions in clinical and billing contexts.

Questions About This Page

How many billable codes are in the F43 range?

Of the 18 codes in this range, 14 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.

What does the F43 range classify?

The range classifies reaction to severe stress, and adjustment disorders. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.

Related References

Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.