ICD-10-CM 2027
ICD-10 code for phobic reaction
From the official ICD-10-CM alphabetic index entry “Reaction › phobic”. Page updated September 29, 2026.
About coding phobic reaction
The ICD-10-CM code for phobic reaction is F40.9 (Phobic anxiety disorder, unspecified).
Within F40, choose F40.9 (Phobic anxiety disorder, unspecified) only when documentation doesn't support a more specific option: agoraphobia (F40.0), social phobias (F40.1), specific (isolated) phobias (F40.2) and other phobic anxiety disorders (F40.8).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 882 (Neuroses Except Depressive, relative weight 0.9952), in MDC 19 (Mental Diseases and Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about phobic reaction ICD-10 codes
What is the ICD-10 code for phobic reaction?
- F40.9 — Phobic anxiety disorder, unspecified.
Is F40.9 billable?
- Yes. F40.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can F40.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict F40.9 as a principal diagnosis.
Is F40.9 a CC or MCC?
- No. F40.9 is neither a CC nor an MCC under MS-DRG v44.0.