F51.01 – Primary insomnia

F51.01 – Primary insomnia

Discover how to use F51.01 when diagnosing primary insomnia. Learn more about this sleep disorder and its symptoms.

By Patricia Buenaventura on Aug 8, 2025.

Fact Checked by Karina Jimenea.

Use Code

F51.01 diagnosis code: Primary insomnia

F51.01 is a diagnostic code from the International Classification of Diseases, 10th Revision (ICD-10-CM), under F51: Sleep disorders not due to a substance or known physiological condition, used to classify medical conditions. It refers to primary insomnia, a specific type of sleep disorder.

Primary insomnia is characterized by difficulty initiating or maintaining sleep or having non-restorative sleep for at least one month. Primary insomnia symptoms can cause significant distress or impairment in various areas of life, such as work, school, or social functioning. It is referred to as "primary" because it is not caused by any other medical condition, substance use, or mental disorder. 

Diagnosing primary insomnia requires ruling out other potential causes of sleep disturbance. This may involve a thorough evaluation by a healthcare professional, including a detailed medical history, physical examination, and sometimes additional tests to exclude other underlying conditions.

Is F51.01 billable?

Yes, this diagnosis code is billable.

Clinical information

Primary insomnia is a chronic sleep disorder characterized by difficulty falling or staying asleep, or waking up too early and not being able to fall back asleep. It is one of several persistent mood (affective) disorders that can significantly impact health and well-being. Symptoms may include fatigue, difficulty concentrating, and irritability during the day. 

Primary insomnia is often caused by psychological factors such as stress or anxiety, but can also be due to medical conditions or medications. Furthermore, other disorders like neurodevelopmental disorders, sleep deprivation, or conditions like sleep apnea may contribute to insomnia. It is important to rule out any other underlying conditions before diagnosing primary insomnia, as these may need to be addressed to effectively treat the disorder.

Treatment for primary insomnia typically involves behavior and lifestyle changes, such as establishing consistent sleep patterns, avoiding caffeine or alcohol before bedtime, and creating a calming nighttime routine. In some cases, medication may also be prescribed to help improve sleep quality. Additionally, cognitive-behavioral therapy can be used to address any underlying mental health issues that may be affecting sleep.

Synonyms include

  • Disturbed sleep
  • Dysomnia
  • Secondary insomnia
  • Sleep disorder
  • Persistent mood disorder

Other ICD-10 codes commonly used for insomnia

These are some of the codes used to diagnose insomnia:

  • F51.02: Adjustment insomnia
  • F51.05: Insomnia due to other mental disorder
  • G47.00: Insomnia, unspecified (Applicable to insomnia disorder, insomnia NOS, etc.)
  • G47.01: Insomnia due to medical condition
  • G47.10: Hyperinsomnia, unspecified
  • Drug-related insomnia codes like (F11.182, F14.182, F15.282, etc.)
  • Alcohol related insomnia codes (F10.182, F10.282, F10.982)

Commonly asked questions

A diagnosis code F51.01 should be used when a person is experiencing difficulty falling asleep or staying asleep due to a primary insomnia disorder, such as stress, depression, or anxiety.

Yes, the F51.01 diagnosis code is generally billable to insurance companies and Medicare.

The common treatments for F51.01 include cognitive behavioral therapy (CBT), medication, good sleep hygiene practices, and lifestyle changes.

Related ICDs

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