Sleep disorders not due to a substance or known physiological condition (F51) ICD-10-CM
The F51 code range covers sleep disorders not due to a substance or known physiological condition with 18 ICD-10-CM diagnosis codes. 15 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
- organic sleep disorders G47
Codes in the F51 Range 18 codes · 15 billable
- F51 Sleep disorders not due to a substance or known physiological conditionNon-billable
- F51.0 Insomnia not due to a substance or known physiological conditionNon-billable
- F51.01 Primary insomnia
- F51.02 Adjustment insomnia
- F51.03 Paradoxical insomnia
- F51.04 Psychophysiologic insomnia
- F51.05 Insomnia due to other mental disorder
- F51.09 Other insomnia not due to a substance or known physiological condition
- F51.1 Hypersomnia not due to a substance or known physiological conditionNon-billable
- F51.11 Primary hypersomnia
- F51.12 Insufficient sleep syndrome
- F51.13 Hypersomnia due to other mental disorder
- F51.19 Other hypersomnia not due to a substance or known physiological condition
- F51.3 Sleepwalking [somnambulism]
- F51.4 Sleep terrors [night terrors]
- F51.5 Nightmare disorder
- F51.8 Other sleep disorders not due to a substance or known physiological condition
- F51.9 Sleep disorder not due to a substance or known physiological condition, unspecified
About the F51 Code Range
ICD-10 codes in the F51 section are used to classify sleep disorders that are not caused by substance use or identifiable physiological conditions. This range covers various forms of insomnia, hypersomnia, and parasomnias like sleepwalking and night terrors, helping healthcare providers specify nonorganic sleep problems.
The F51 codes assist in recognizing conditions such as primary insomnia (also called nonorganic insomnia or hypersomnia of non-organic origin), which involves difficulty sleeping without an external cause. Adjustment insomnia (transient insomnia) and psychophysiologic insomnia (chronic insomnia) are included under this section. It also covers hypersomnia types, including primary hypersomnia and insufficient sleep syndrome, where trouble staying awake or getting adequate rest occurs independently of other disorders. Parasomnias like sleepwalking (somnambulism), sleep terrors (night terrors), and nightmare disorder are coded here to specify these unusual sleep behaviors. The section's “other” and “unspecified” categories allow coding of less common or poorly defined nonorganic sleep disorders. These codes help medical coders identify non-substance-related sleep disturbances precisely, facilitating accurate diagnosis and treatment tracking.
Questions About This Page
How many billable codes are in the F51 range?
Of the 18 codes in this range, 15 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the F51 range classify?
The range classifies sleep disorders not due to a substance or known physiological condition. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
