ICD-10 for therapists

F41.1 — Generalized anxiety disorder

Reviewed by Albert Wong, PhD, Clinical Psychologist · Updated July 29, 2026

Excessive, difficult-to-control worry across multiple domains for six months or more, with somatic tension symptoms — the most commonly billed anxiety diagnosis.

Code: F41.1 (ICD-10-CM)
Common CPT pairings: 90791 · 90834 · 90837

Clinical picture

Worry must span multiple life domains and persist six months; three or more associated symptoms (restlessness, fatigue, concentration, irritability, tension, sleep) in adults.
Frequently comorbid with depression — when criteria for both are met, code both.
GAD-7 provides a defensible severity baseline and progress trend.

Documentation tips

Document the six-month duration and the multi-domain character of worry explicitly; that is what separates GAD from situational anxiety.
A GAD-7 trend across treatment is persuasive evidence of medical necessity for continued care — or a clean discharge story.

Billing notes

Well supported for weekly psychotherapy across payers. Pairing with measurement-based care strengthens reauthorization requests.

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This reference summarizes ICD-10-CM coding conventions and common billing practice for licensed clinicians. It is not medical, legal, or payer-specific billing advice; diagnosis requires clinical evaluation, and payer policies vary. Verify codes against the current ICD-10-CM release.