Is ICD-10-CM code Y99 billable?

No, Y99 (External cause status) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code Y99 belong to?

Y99 belongs to Chapter 20 of the ICD-10-CM tabular list: V00–Y99 (External Causes of Morbidity).

Y99Not billable, use a more specific code below

External cause status

In Supplementary factors related to causes of morbidity classified elsewhere (Y90-Y99), chapter 20: External Causes of Morbidity

5 billable codes under Y99: none are a CC or MCC; none map to an HCC.

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Covers how to report external cause codes (V00-Y99) describing cause, intent, place, activity, and status. They are never principal or first-listed, and reporting is voluntary unless required.

General External Cause Coding Guidelines (page 88)
Place of Occurrence Guideline (page 89)
Activity Code (page 89)
Place of Occurrence, Activity, and Status Codes Used with other External Cause Code (page 89)
If the Reporting Format Limits the Number of External Cause Codes (page 90)
Multiple External Cause Coding Guidelines (page 90)
Child and Adult Abuse Guideline (page 90)
Unknown or Undetermined Intent Guideline (page 91)

Read Section I.C.20 (page 87), 3 more topics

All codes under Y99

Y99 can't be used on a claim. Pick a billable code below; grey headings group them.

Y99 MS-DRGs

This code does not group to an MS-DRG as a principal diagnosis.

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.