Current
R99 — Ill-defined and unknown cause of mortality
Part of Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified , block Ill-defined and unknown cause of mortality (R99) .
Official Notes
Inclusion Terms
Death (unexplained) NOS
Inclusion Terms
Unspecified cause of mortality
Child Codes
R99 has no child codes in the FY 2027 release -- it is used on its own.
FY 2027 effective October 1, 2026 · CDC NCHS and CMS