Alphabetic Index FY2027

F51.9

Sleep disorder not due to a substance or known physiological condition, unspecified

FY2027Chapter 5: Mental, Behavioral and Neurodevelopmental disorders/F50–F59 Behavioral syndromes associated with physiological disturbances and physical factors

BillableComplete code, valid to report
Care settingsHome Health Primary · Behavioral HealthIPF Primary · MS-DRG 887

F51.9 (also written F519) is a billable ICD-10-CM diagnosis code for sleep disorder not due to a substance or known physiological condition, unspecified. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 15 codes in category F51 (Sleep disorders not due to a substance or known physiological condition). The Alphabetic Index lists it under 10 entries. Its coding notes include 2 Excludes2 entries.

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Inherited from F51 Sleep disorders not due to a substance or known physiological condition
  • organic sleep disorders (G47.-)
Also from chapter/block level (1 note)
Inherited from Chapter 5 Mental, Behavioral and Neurodevelopmental disorders
  • symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Home Health Primary

Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the Behavioral Health clinical group.

Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026

IPF Primary

IPF MS-DRG adjustment. A principal diagnosis of this code groups to this MS-DRG:

MS-DRGDescriptionFactor
887Other mental disorder diagnoses1.00
A principal diagnosis that groups to none of the 19 designated MS-DRGs gets no MS-DRG adjustment. Otherwise the claim still receives the federal per diem base rate and the other adjustments.

Source: CMS IPF PPS FY 2027 final rule (CMS-1847-F), Addendum A; code lists from the CMS MS-DRG Definitions Manual v44; effective for discharges on or after October 1, 2026

Includes

Further defines or gives examples of the content of the category.

Also from chapter/block level (1 note)
Inherited from Chapter 5 Mental, Behavioral and Neurodevelopmental disorders
  • disorders of psychological development

Inclusion terms

Conditions classified to this code.

This code
  • Emotional sleep disorder NOS

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 10 entries