ICD-10 Code F40.228 – Other natural environment type phobia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F40.228 – Other natural environment type phobia
What it is
F40.228 identifies a specific phobia involving fear of natural environmental situations or objects not otherwise classified. Use it when the record clearly describes an irrational, persistent fear tied to a natural setting.
Clinical signs
Clinical features vary; refer to documentation. Typical findings include marked anxiety, avoidance, and distress when exposed to the feared natural environment, with symptoms out of proportion to the actual risk.
When to use this code
Use this code when the clinician documents a phobia related to a natural environment and does not specify a more precise ICD-10-CM option. It may apply in behavioral health notes, psychiatric evaluations, or problem lists. Confirm the fear is persistent and clinically significant.
Do not use for
Do not use this code for ordinary dislike, transient worry, or generalized anxiety without a specific natural-environment trigger. Check documentation if the fear is better described by another phobia code.
Coding tip
Code only when the chart names a natural-environment phobia and documents its clinical relevance; otherwise, check documentation.