Emergency: 119
AMDA-IMIC

R99 Ill-defined and unknown cause of mortality

Billable

Block: Ill-defined and unknown cause of mortality (R99)

Includes

  • Death (unexplained) NOS
  • Unspecified cause of mortality
✓
This category is a complete, billable diagnosis code.

No additional specificity is required — submit R99 directly on claims and documentation without a subcode extension.

Last reviewed: September 2026