2026 ICD-10-CM Diagnosis Code S04.819SInjury of olfactory [1st ] nerve, unspecified side, sequela
S04.819S is a billable ICD-10-CM diagnosis code for injury of olfactory [1st ] nerve, unspecified side, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is exempt from POA reporting. Coders also document this condition as disorder of olfactory nerve. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Injury, sequela.
Code Identity
Code Classification
Present on Admission (POA)Billing
S04.819S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Disorder of olfactory nerve
- Disorder of smell
- Injury of olfactory nerve
- Loss of sense of smell
- Traumatic anosmia
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Injury of cranial nerve (S04). Use the following options for the applicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Peripheral Nerve Disorders
Nerves are like wires that carry messages back and forth between your brain and your body. Your peripheral nerves branch off from your brain and spinal cord and connect to all parts of your body, including your muscles and organs.
The full article covers:
- What are peripheral nerves?
- What are peripheral nerve disorders?
- What causes peripheral nerve disorders?
- What are the symptoms of peripheral nerve disorders?
- How are peripheral nerve disorders diagnosed?
- What are the treatments for peripheral nerve disorders?
- Can peripheral nerve disorders be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S04.819S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S04.819SOverview
Is S04.819S (Injury of olfactory [1st ] nerve, unspecified side) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report injury of olfactory [1st ] nerve, unspecified side, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in S04.819S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the injury of olfactory [1st ] nerve, unspecified side itself has resolved, not the original event.
Is S04.819S exempt from POA reporting?
Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for injury of olfactory [1st ] nerve, unspecified side, sequela on inpatient claims.
What is the ICD-9 equivalent of S04.819S?
Under the General Equivalence Mappings, injury of olfactory [1st ] nerve, unspecified side, sequela converts to ICD-9-CM 907.1 (late eff cran nerve inj). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
