ICD-10-CM 2027 diagnosis code

Y99External cause status

Not billable — use a more specific code

Y99 is a header code, so it can't be reported by itself. Choose one of the 5 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About Y99

Y99 is the ICD-10-CM diagnosis code for external cause status. It belongs to block Y90-Y99 (Supplementary factors related to causes of morbidity classified elsewhere) and chapter 20 (external causes of morbidity). It is a header code, so it can't be reported by itself; one of its 5 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: Y99.0 (pay), Y99.1 (activity), Y99.2 (activity), Y99.8 (status) and Y99.9 (status).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under Y99

Coding notes

Note

A single code from category Y99 should be used in conjunction with the external cause code(s) assigned to a record to indicate the status of the person at the time the event occurred.

Notes that apply from higher levels

Instructions written at a parent level also apply to Y99.

Broader instructions also apply from Y90-Y99 Supplementary factors related to causes of morbidity classified elsewhere and Chapter 20: External causes of morbidity.

Codes whose notes reference Y99

Y93Note

Code history

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about Y99

Is Y99 billable?: No. Y99 is a header code. Report one of its more specific subcodes instead.