ICD-10-CM 2027
ICD-10 code for death
From the official ICD-10-CM alphabetic index entry “Death (cause unknown) (of) (unexplained) (unspecified cause)”. Page updated September 29, 2026.
About coding death
The ICD-10-CM code for death is R99 (Ill-defined and unknown cause of mortality). The official index lists 4 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on R99.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 951 (Other Factors Influencing Health Status, relative weight 0.5577), in MDC 23 (Factors Influencing Health Status and Other Contacts with Health Services), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
More specific death codes (official index)
Common questions about death ICD-10 codes
What is the ICD-10 code for death?
- R99 — Ill-defined and unknown cause of mortality. More specific codes apply when the documentation supports them: G93.82, Z82.41, Z86.74, Z63.4.
What is the ICD-10 code for brain death?
- G93.82 — Brain death.
What is the ICD-10 code for family member death?
- Z63.4 — Disappearance and death of family member.
Is R99 billable?
- Yes. R99 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can R99 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict R99 as a principal diagnosis.
Is R99 a CC or MCC?
- No. R99 is neither a CC nor an MCC under MS-DRG v44.0.