R99
BillableIll-defined and unknown cause of mortality
R99 is the ICD-10-CM code for Ill-defined and unknown cause of mortality. It is a billable, specific code valid for reimbursement.
- Status
- Billable
- Chapter
- R00-R99
- Edition
- FY2026
R00-R99 Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
Includes
- •Death (unexplained) NOS
- •Unspecified cause of mortality
Frequently asked questions
- What is ICD-10 code R99?
- R99 is the ICD-10-CM code for "Ill-defined and unknown cause of mortality". It falls under R00-R99 Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified.
- Is R99 a billable code?
- Yes — R99 is a billable, specific ICD-10-CM code valid for reimbursement.
Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.
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