S04.899A — Injury of other cranial nerves, unspecified side, initial encounter
Is S04.899A billable?
Yes, but S04.899A will trip a Medicare edit. S04.899A is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, CMS lists S04.899A under Medicare Code Editor edit 20, “Unspecified code” — meaning a code specifying laterality (right, left or bilateral) exists in the same family. On an inpatient claim this triggers the edit, because CMS holds that there are very limited circumstances in which laterality cannot be documented.
S04.899A at a glance
| Code | S04.899A |
|---|---|
| Description | Injury of other cranial nerves, unspecified side, initial encounter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "A" | initial encounter |
What does the 7th character "A" mean in S04.899A?
In S04.899A, the 7th character A means initial encounter. The 7th character is required for S04.899A to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
What Medicare edits apply to S04.899A?
The Medicare Code Editor screens inpatient claims before they are grouped. These edits name S04.899A directly.
A code specifying laterality (right, left or bilateral) exists in the same family. CMS holds that there are very limited circumstances in which laterality cannot be documented.
Which MS-DRGs does S04.899A group to?
S04.899A sits in MDC 01 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 073Cranial and Peripheral Nerve Disorders with MCCmedical
- 074Cranial and Peripheral Nerve Disorders without MCCmedical
As a secondary diagnosis, S04.899A is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is S04.899A listed in the Alphabetic Index?
The Alphabetic Index lists these routes under S04.89, the nearest indexed parent of S04.899A. Use them to find the family, then select the specific code.
- Injury › nerve NEC › glossopharyngeal
- Injury › nerve NEC › hypoglossal
- Injury › nerve NEC › vagus
- Injury › nerve NEC › glossopharyngeal › specified type NEC
- Injury › nerve NEC › hypoglossal › specified type NEC
- Injury › nerve NEC › vagus › specified type NEC
- Injury › nerve NEC › cranial › specified › nerve NEC
- Injury › nerve NEC › cranial › specified › nerve NEC › contusion
Code first — inherited from S04
The underlying condition below must be sequenced before S04.899A. S04.899A describes a manifestation and cannot be the principal or first-listed diagnosis.
- any associated intracranial injury (S06.-)
Use additional code — inherited from Chapter 19
Report an additional code alongside S04.899A to fully describe the condition. S04.899A is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of S04.899A, but a patient may have both at the same time. When documentation supports it, S04.899A and the excluded code may both be reported.
Excludes2 — not included here — inherited from S00-S09
The conditions below are not part of S04.899A, but a patient may have both at the same time. When documentation supports it, S04.899A and the excluded code may both be reported.
- burns and corrosions (T20-T32)
- effects of foreign body in ear (T16)
- effects of foreign body in larynx (T17.3)
- effects of foreign body in mouth NOS (T18.0)
- effects of foreign body in nose (T17.0-T17.1)
- effects of foreign body in pharynx (T17.2)
- effects of foreign body on external eye (T15.-)
- frostbite (T33-T34)
- insect bite or sting, venomous (T63.4)
Code also — inherited from S00-S09
Two codes may be needed to describe the condition fully. Whether S04.899A is sequenced first depends on the reason for the encounter.
- for any associated infection
Code also — inherited from S04
Two codes may be needed to describe the condition fully. Whether S04.899A is sequenced first depends on the reason for the encounter.
How long has S04.899A existed?
S04.899A has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.