2026 ICD-10-CM Diagnosis Code F43Reaction to severe stress, and adjustment disorders

ICD-10-CM Codes›F01–F99›F40-F48›F43

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

F43 is a non-billable ICD-10-CM category code for reaction to severe stress, and adjustment disorders, so it cannot be submitted on claims. Use a more specific code from this category instead, such as F43.0, F43.10, F43.11, and F43.12.

Code Identity

ICD-10-CM Code
F43
Billable Status
No — Non-Billable Category
Code Describes
Reaction to severe stress, and adjustment disorders
Short Description
Reaction to severe stress, and adjustment disorders
Same as the full description in the CMS dataset.
Chapter
F40-F48
Anxiety, dissociative, stress-related, somatoform and other nonpsychotic mental 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 CodeF43Reaction to severe stress, and adjustment disorders

Specific Coding for Reaction to severe stress, and adjustment disordersOverview

Non-specific codes like F43 require more characters. Use one of these billable codes instead:

  • Use F43.0 for Acute stress reaction

  • F43.1 for Post-traumatic stress disorder (PTSD)

  • Use F43.10 for Post-traumatic stress disorder, unspecified

  • Use F43.11 for Post-traumatic stress disorder, acute

  • Use F43.12 for Post-traumatic stress disorder, chronic

  • F43.2 for Adjustment disorders

  • Use F43.20 for Adjustment disorder, unspecified

  • Use F43.21 for Adjustment disorder with depressed mood

  • Use F43.22 for Adjustment disorder with anxiety

  • Use F43.23 for Adjustment disorder with mixed anxiety and depressed mood

  • Use F43.24 for Adjustment disorder with disturbance of conduct

  • Use F43.25 for Adjustment disorder with mixed disturbance of emotions and conduct

  • Use F43.29 for Adjustment disorder with other symptoms

  • F43.8 for Other reactions to severe stress

  • Use F43.81 for Prolonged grief disorder

  • Use F43.89 for Other reactions to severe stress

  • Use F43.9 for Reaction to severe stress, unspecified

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.

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 F43Overview

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

No. This is a category header that groups the codes for reaction to severe stress, and adjustment disorders, and headers cannot be submitted on claims. Claims for reaction to severe stress, and adjustment disorders need a more specific code from this category, such as F43.0, F43.10, and F43.11.