ICD10
ICD-10 Code F51.0: Insomnia not due to a substance or known physiological condition
Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026
What is this code?
ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Mental, Behavioral and Neurodevelopmental disorders (F01-F99).
When is it used?
- May be used when a clinician documents insomnia not due to a substance or known physiological condition in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
- This entry may represent a broader category rather than the most specific billable code.
Code hierarchy
chapter
5Mental, Behavioral and Neurodevelopmental disorders (F01-F99)
block
F50-F59Behavioral syndromes associated with physiological disturbances and physical factors
category
F51Sleep disorders not due to a substance or known physiological condition
currentF51
Official coding notes
Excludes2 (may code together if documented)
- alcohol related insomnia (F10.182, F10.282, F10.982)
- drug-related insomnia (F11.182, F11.282, F11.982, F13.182, F13.282, F13.982, F14.182, F14.282, F14.982, F15.182, F15.282, F15.982, F19.182, F19.282, F19.982)
- insomnia NOS (G47.0-)
- insomnia due to known physiological condition (G47.0-)
- organic insomnia (G47.0-)
- sleep deprivation (Z72.820)
Where you may see this code
You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.
Related codes
Sibling codes
F51.1Hypersomnia not due to a substance or known physiological conditionF51.3Sleepwalking [somnambulism]billableF51.4Sleep terrors [night terrors]billableF51.5Nightmare disorderbillableF51.8Other sleep disorders not due to a substance or known physiological conditionbillableF51.9Sleep disorder not due to a substance or known physiological condition, unspecifiedbillable
Mapped diagnoses and classifications
SNOMED_CT 288421000119100high
Hyposomnia co-occurrent and due to psychological disorder
Source: SNOMED International ICD-10 map
SNOMED_CT 24121004high
Insomnia disorder related to another mental disorder
Source: SNOMED International ICD-10 map
SNOMED_CT 192454004high
Nonorganic insomnia
Source: SNOMED International ICD-10 map
SNOMED_CT 3972004high
Primary insomnia
Source: SNOMED International ICD-10 map
SNOMED_CT 425832009high
Psychophysiologic insomnia
Source: SNOMED International ICD-10 map
Coding guidelines
Compatibility
Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
F51.0
Replacement codes
F51.01 — Primary insomniaF51.02 — Adjustment insomniaF51.03 — Paradoxical insomniaF51.04 — Psychophysiologic insomniaF51.05 — Insomnia due to other mental disorderF51.09 — Other insomnia not due to a substance or known physiological condition
Common synonyms
Insomnia not due to a substance or known physiological condition
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.