R99 is a billable/specific diagnosis code from the 2026 ICD-10-CM used to classify the following condition: Ill-defined and unknown cause of mortality.
Inclusion term
Death (unexplained) NOS
Unspecified cause of mortality
Versions
2026
No changes
2025
No changes
2024
No changes
2023
No changes
2022
No changes
2021
No changes
2020
No changes
2019
No changes
2018
No changes
2017
No changes
2016
New code