ICD-10-CM 2027 diagnosis code

F43Reaction to severe stress, and adjustment disorders

Not billable — use a more specific code

F43 is a header code, so it can't be reported by itself. Choose one of the 5 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About F43

F43 is the ICD-10-CM diagnosis code for reaction to severe stress, and adjustment disorders. It belongs to block F40-F48 (anxiety, dissociative, stress-related, somatoform and other nonpsychotic mental disorders) and chapter 5 (mental, Behavioral and Neurodevelopmental disorders). It is a header code, so it can't be reported by itself; one of its 5 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: F43.0 (reaction), F43.1 ((PTSD)), F43.2 (disorders), F43.8 (stress) and F43.9 (unspecified).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under F43

Notes that apply from higher levels

Instructions written at a parent level also apply to F43.

Broader instructions also apply from Chapter 5: Mental, Behavioral and Neurodevelopmental disorders.

Code history

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about F43

Is F43 billable?: No. F43 is a header code. Report one of its more specific subcodes instead.