ICD-10 Code F40.240 – Claustrophobia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F40.240 – Claustrophobia
What it is
Claustrophobia is an anxiety disorder involving a marked fear of enclosed or confined spaces. Use this code when documentation identifies the condition as claustrophobia.
Clinical signs
Patients may report intense fear, panic, avoidance, or distress in elevators, small rooms, tunnels, or similar settings. Clinical features vary; refer to documentation.
When to use this code
Assign F40.240 when the provider documents claustrophobia as the diagnosis, whether current or being evaluated. Use it for visits where the fear of enclosed spaces is the primary reason for assessment or affects care, such as imaging or procedures.
Do not use for
Do not use this code for general anxiety, panic disorder, or other phobias unless claustrophobia is specifically documented. Check documentation if the record only notes “anxiety in MRI” without a clear diagnosis.
Coding tip
Code the documented phobia, not the setting that triggered it.