ICD-10 Code F45.21 – Hypochondriasis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F45.21 – Hypochondriasis
What it is
F45.21 identifies hypochondriasis, a disorder marked by persistent fear of having a serious illness despite limited or no medical evidence. You should use it when the concern itself is the primary diagnosis.
Clinical signs
Typical features include repeated health worries, frequent body checking, and ongoing reassurance-seeking. Clinical features vary; refer to documentation, and confirm that the concern is excessive or persistent.
When to use this code
Use F45.21 when the record documents hypochondriasis or illness anxiety as the main reason for evaluation. It may also fit when the patient has persistent preoccupation with disease, repeated negative workups, and no better documented explanation.
Do not use for
Do not use this code for a confirmed medical illness with appropriate concern. Also avoid it when documentation supports another anxiety, somatic symptom, or psychotic disorder instead.
Coding tip
Code from the provider’s documented diagnosis and note whether the concern is excessive, persistent, or unsupported by findings.