2026 ICD-10-CM Diagnosis Code F51.9Sleep disorder not due to a substance or known physiological condition, unspecified

ICD-10-CM Codes›F01–F99›F50-F59›F51

ICD-10-CM F51.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

F51.9 is a billable ICD-10-CM diagnosis code for sleep disorder not due to a substance or known physiological condition, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 887. Coders also document this condition as non-organic sleep disorder. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sleep wake disorders.

Code Identity

ICD-10-CM Code
F51.9
Billable Status
Yes — Valid for Submission
Code Describes
Sleep disorder not due to a substance or known physiological condition, unspecified
Short Description
Sleep disorder not due to a sub or known physiol cond, unsp
Parent Code
F51
Sleep disorders not due to a substance or known physiological condition

Code Classification

ChapterF01–F99Mental and behavioural disorders
SectionF50-F59Behavioral syndromes associated with physiological disturbances and physical factors
CategoryF51Sleep disorders not due to a substance or known physiological condition
This CodeF51.9Sleep disorder not due to a substance or known physiological condition, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Non-organic sleep disorder
  • Sleep drunkenness

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Emotional sleep disorder NOS

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS016
Sleep wake disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Sleep Disorders

Sleep is a complex biological process. While you are sleeping, you are unconscious, but your brain and body functions are still active. They are doing a number of important jobs that help you stay healthy and function at your best. So when you don't get enough quality sleep, it does more than just make you feel tired.

The full article covers:

  • What is sleep?
  • What are sleep disorders?
  • What causes sleep disorders?
  • What are the symptoms of sleep disorders?
  • How are sleep disorders diagnosed?
  • What are the treatments for sleep disorders?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert F51.9 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
307.40 Nonorganic sleep dis NOS
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About F51.9Overview

Is F51.9 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report sleep disorder not due to a substance or known physiological condition, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does F51.9 group to?

When sleep disorder not due to a substance or known physiological condition, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 887 (other Mental Disorder Diagnoses), which carries a relative weight of 1.0709. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of F51.9?

Under the General Equivalence Mappings, sleep disorder not due to a substance or known physiological condition, unspecified converts to ICD-9-CM 307.40 (nonorganic sleep dis NOS). The mapping is a direct match.