F43.9 Reaction to severe stress, unspecified

Billable ICD-10-CM code, FY2026.

Applicable to

• Trauma and stressor-related disorder, NOS
• Unspecified trauma and stressor-related disorder

MS-DRG index

Defines the logic of DRG(s) 882 in MDC 19.

Approximate ICD-9-CM (GEMs)

• 309.9 Unspecified adjustment reaction (approximate)

Code annotations containing back-references to F43.9

Back-references to F43

• Type 2 Excludes: F93.0 Separation anxiety disorder of childhood ("nonpsychotic mental disorders (F40-F48)")

Diagnosis Index entries for F43.9

• Disorder (of) › stress
• Disorder (of) › trauma and stressor-related NOS
• Disorder (of) › trauma and stressor-related NOS › unspecified
• Reaction › stress (severe)
• Stress
• Stress › reaction

Nearby codes

• F43.25 Adjustment disorder with mixed disturbance of emotions and conduct
• F43.29 Adjustment disorder with other symptoms
• F43.8 Other reactions to severe stress
• F43.81 Prolonged grief disorder
• F43.89 Other reactions to severe stress
• F43.9 Reaction to severe stress, unspecified (this code)