F51.01 — Primary insomnia

F51.01

ICD-10 Chapter 5: Mental, Behavioral & Neurodevelopmental — illustrative image — Chapter 5: Mental, behavioral and neurodevelopmental disorders (F01–F99) — illustrative image

What this code means

Primary insomnia is persistent difficulty falling or staying asleep not caused by another medical or mental condition.

Also called: primary insomnia, insomnia disorder.

When this code is used

Used for primary insomnia.

Where it sits in ICD-10-CM

Code F51.01 belongs to Chapter 5: Mental, behavioral and neurodevelopmental disorders, which covers codes F01–F99 in the FY2027 ICD-10-CM tabular list. The official description above is copied verbatim from the CDC/NCHS FY2027 code file.

Related symptoms

Frequently asked questions

What is ICD-10-CM code F51.01?

F51.01 is the ICD-10-CM diagnosis code for “Primary insomnia”. Primary insomnia is persistent difficulty falling or staying asleep not caused by another medical or mental condition.

When is code F51.01 used?

Used for primary insomnia. It belongs to Chapter 5 of ICD-10-CM (Mental, behavioral and neurodevelopmental disorders).

This guide explains ICD-10-CM codes in plain language for patients, students and other readers. It is educational information only — not coding, billing or medical advice. The code recorded for any real encounter is assigned from the full clinical documentation by the treating team and qualified coders, and only they can decide which code fits a specific case.